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24 pages, 9197 KiB

Open AccessArticle

Using Neural Networks as a Data-Driven Model to Predict the Behavior of External Gear Pumps

by Benjamin Peric, Michael Engler, Marc Schuler, Katja Gutsche and Peter Woias

Processes 2024, 12(3), 526; https://doi.org/10.3390/pr12030526 - 6 Mar 2024

Viewed by 1118

Abstract

This study presents a method for predicting the volume flow output of external gear pumps using neural networks. Based on operational measurements across the entire energy chain, the neural network learns to map the internal leakage of the pumps in use and consequently [...] Read more.

This study presents a method for predicting the volume flow output of external gear pumps using neural networks. Based on operational measurements across the entire energy chain, the neural network learns to map the internal leakage of the pumps in use and consequently to predict the output volume flow over the entire operating range of the underlying dosing process. As a consequence, the previously used volumetric flow sensors become obsolete within the application itself. The model approach optimizes the higher-level dosing system in order to meet the constantly growing demands of industrial applications. We first describe the mode of operation of the pumps in use and focus on the internal leakage of external gear pumps, as these primarily determine the losses of the system. The structure of the test bench and the data processing for the neural network are discussed, as well as the architecture of the neural network. An error flow rate of approximately 1% can be achieved with the presented approach considering the entire operating range of the pumps, which until now could only be realized with multiple computationally intensive CFD simulations. The results are put into perspective by a hyperparameter study of possible neural architectures. The biggest obstacle considering the industrial scaling of this solution is the data generation process itself for various operating points. To date, an individual dataset is required for each pump because the neural architectures used are difficult to transfer, due to the tolerances of the manufactured pumps. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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18 pages, 16189 KiB

Open AccessEditor’s ChoiceArticle

Design and Sensitivity Analysis of Mechanically Actuated Digital Radial Piston Pumps

by Keith Pate, James R. Marschand, Farid Breidi, Tawfiq Salem and John Lumkes

Processes 2024, 12(3), 504; https://doi.org/10.3390/pr12030504 - 29 Feb 2024

Viewed by 1462

Abstract

One major challenge in fluid power is the improvement and optimization of the efficiency of mobile hydraulic systems. Conventional fluid power systems often exhibit relatively low overall efficiencies caused by inefficiencies in the various components, such as a prime mover, variable displacement pump, [...] Read more.

One major challenge in fluid power is the improvement and optimization of the efficiency of mobile hydraulic systems. Conventional fluid power systems often exhibit relatively low overall efficiencies caused by inefficiencies in the various components, such as a prime mover, variable displacement pump, valves, fittings, hoses, and actuators. While each component contributes to the losses in the overall system, the pump converts the mechanical shaft energy from the prime mover to energy transmitted hydraulically and is one of the most crucial components impacting overall system efficiency. Using on/off technologies, new pump architectures have enabled the opportunity to increase the efficiency over conventional designs using positive sealing valves in place of conventional port plate designs. This work proposes, investigates, and assesses the development and optimization of a digital variable displacement pump using a novel cam actuation technique on radial piston pumps. The novelty of this work is the development and parameter optimization of a mechanically actuated digital radial piston pump that can achieve high efficiencies from minimum to maximum displacement compared to common conventional variable displacement pump technologies. In this study, a sensitivity analysis is conducted to study the parameters of the system to optimize the pump. The parameters assessed in this study include: the valve bore size, cam transition and compression angles, piston diameter, and dead volume in the pumping chamber. The simulation results show that after optimizing the parameters of the system, the pump in design could reach a maximum efficiency of approximately 93% and was capable of upholding efficiencies above 80% between 30–100% displacement. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 6599 KiB

Open AccessArticle

Analysis of Solid-Liquid Two-Phase Flow in the Area of Rotor and Tailpipe

by Gengda Xie, Qifei Li, Lu Xin and Zhanyong Li

Processes 2023, 11(12), 3382; https://doi.org/10.3390/pr11123382 - 6 Dec 2023

Cited by 1 | Viewed by 877

Abstract

In order to study the internal flow state and wear law of a bulb cross-flow unit based on the particle non-uniform phase model in the Euler–Euler method, the solid-liquid two-phase flow condition of the hydraulic turbine under different solid-phase diameters, concentrations, and guide [...] Read more.

In order to study the internal flow state and wear law of a bulb cross-flow unit based on the particle non-uniform phase model in the Euler–Euler method, the solid-liquid two-phase flow condition of the hydraulic turbine under different solid-phase diameters, concentrations, and guide vane openings is calculated. The results show that (1) Under the same solid-phase physical parameters, the distribution of solid-phase concentration on the working surface of the blade is positively correlated with the opening degree of the guide vane, the concentration of the solid phase on the back of the blade is negatively correlated with the opening degree of the guide vane. (2) The addition of the solid phase changes the time-domain period of pressure pulsations at the rotor inlet and the tailpipe inlet under clear water conditions, and the tailpipe pressure pulsation coefficient decreases with increasing solid-phase concentration. The pressure pulsation coefficient increases with increasing solid-phase diameter and concentration at the inlet of the rotor. (3) Numerical simulation of the wear characteristics of cross-flow turbine by Finne’s wear model reveals that the two-phase flow condition with high concentration, large particle size and small openings has a more serious effect on turbine blade wear. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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18 pages, 12869 KiB

Open AccessArticle

Investigation on the Impact of Trailing Edge Stacking Styles on Hydraulic Performance in the Multistage Submersible Pump Space Diffuser

by Hui Zhang, Puyu Cao, Dan Ni, Xuran Gong, Bo He and Rui Zhu

Processes 2023, 11(12), 3358; https://doi.org/10.3390/pr11123358 - 3 Dec 2023

Viewed by 1053

Abstract

To investigate the effect of the different wrap angles from the hub to the shroud surface in the space diffuser (i.e., the trailing edge stacking style) on the principle of corner separation vortex flow, a numerical simulation method has been conducted in a [...] Read more.

To investigate the effect of the different wrap angles from the hub to the shroud surface in the space diffuser (i.e., the trailing edge stacking style) on the principle of corner separation vortex flow, a numerical simulation method has been conducted in a multistage submersible pump. Building a linear equation on the profile line of the diffuser trailing edge to optimize the wrap angle on every spanwise from the hub to the shroud, and the mapping response relationship between the wrap angle difference and the hydraulic performance in the space diffuser has been analyzed. Under the variable wrap angle difference (

Δ ϕ = ϕ_{h u b} - ϕ_{s h r o u d}

), the secondary flows in different directions, non-uniformity, diffuser efficiency, and pressure recovery are compared. The positive wrap angle difference (i.e., the shroud wrap angle is smaller than the hub one) improves the strength of the secondary flow and partly corner separation vortex in the diffuser, so the hydraulic characteristic of positive cases is better than the negative wrap angle difference. Moreover, in scheme A (in which the hub wrap angle is constant and the shroud wrap angle decreasing), the transversal secondary flow has been weakened, the low-energy fluid located in the corner has been suppressed, the extensional secondary flow has been increased, the diffuser hydraulic performance has been improved, and unidirectionally increases with the wrap angle difference increasing. When the shroud wrap angle is constant, the extensional secondary flow has been enhanced by the increasing hub wrap angle. Meanwhile, the increasing extensional secondary flow has been countered by the deteriorating extensional flow at the diffuser inlet and transversal secondary flow, the diffuser hydraulic performance increases and then decreases as the wrap angle difference increases, with an optimal wrap angle difference is about 20°. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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20 pages, 11208 KiB

Open AccessArticle

Flow Control in Multiphase Pumps Based on Separated Trailing Edge Flap

by Juping Zhou, Wei Han, Rennian Li, Xiaoning Ma, Haojie Wang and Wangxu Li

Processes 2023, 11(11), 3066; https://doi.org/10.3390/pr11113066 - 26 Oct 2023

Cited by 1 | Viewed by 1041

Abstract

In developing and transporting significant oil fields in deep-sea environments, multiphase pumps are considered crucial energy conversion equipment. Ensuring their safe, efficient, and stable operation is currently a primary focus of research. The intermittent aggregation of the gas phase at the trailing edge [...] Read more.

In developing and transporting significant oil fields in deep-sea environments, multiphase pumps are considered crucial energy conversion equipment. Ensuring their safe, efficient, and stable operation is currently a primary focus of research. The intermittent aggregation of the gas phase at the trailing edge flap of the impeller blades in multiphase pumps can lead to periodic and significant fluctuations in flow rate and outlet pressure, posing a threat to the overall operational safety of the pump system. Based on aerodynamic principles, this paper presents the design of a separate trailing edge flap for the impeller blades. The inner nodal method is applied to determine the design scheme of the trailing edge flap for the multiphase pump. A numerical approach is employed to analyze the impact of the flap deflection angle on the internal flow characteristics to provide theoretical guidance for the structural optimization of multiphase pumps. The results indicate that the influence of the deflection angle on the pump efficiency is complex and affected by a critical angle value. When the deflection angle is below the critical value, the trailing edge flap can effectively reduce the formation of energy dissipation vortices and radial pressure gradients within the impeller channel, enabling a significant improvement in the gas-phase aggregation phenomenon caused by gas–liquid separation. However, additional energy losses occur at the connection between the trailing edge flap and the main blade body for deflection angles exceeding the critical value. When the trailing edge flap length is 0.25 l and the deflection angle is 5°, the efficiency is improved by 3.4% compared to the original model. Consequently, the pressurization capacity of the pump is compromised. In the design and application of trailing edge flaps, a careful balance between various factors is required to ensure both the stability and high efficiency of the pump system. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 11676 KiB

Open AccessArticle

Research on the Performance of a Centrifugal Aviation Fuel Pump Based on Response Surface Methodology

by Jianbo Zhou, Dongjing He, Rui Zhang and Weidong Zhao

Processes 2023, 11(11), 3055; https://doi.org/10.3390/pr11113055 - 24 Oct 2023

Cited by 1 | Viewed by 1181

Abstract

The performance of centrifugal aviation fuel pumps can be crucial in determining aircraft efficiency and safety. Here, we delve into the intricate interplay between flight altitude and flow rate on pump performance. Employing the central composite design method, we characterized the relationship between [...] Read more.

The performance of centrifugal aviation fuel pumps can be crucial in determining aircraft efficiency and safety. Here, we delve into the intricate interplay between flight altitude and flow rate on pump performance. Employing the central composite design method, we characterized the relationship between these parameters and the pump’s head and efficiency. Our analysis, underpinned by response surface methodology, revealed distinct optimal operating conditions at 10,000 m and 12,000 m flight altitudes, pinpointed at flow rates of 1.1016 Q and 1.1222 Q, respectively. Moreover, the emergence and growth of cavitation regions with increasing flow rates underscore the challenges in pump operation. Significantly, we identify rotor–stator interactions as a dominant influence on pressure fluctuations, especially near the impeller exit. These findings not only elucidate the operational dynamics of aviation fuel pumps but also pave the way for advanced pump designs and optimizations. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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12 pages, 3117 KiB

Open AccessEditor’s ChoiceArticle

Effect of Cavitating Hydraulic Elements on Pump Characteristics

by Jana Jablonská, Milada Kozubková, Sylva Drábková and Tomáš Blejchař

Processes 2023, 11(9), 2592; https://doi.org/10.3390/pr11092592 - 30 Aug 2023

Cited by 1 | Viewed by 1348

Abstract

The effective and reliable performance of any pump can be significantly impacted by the piping system design. One of the essential points is the pump suction pipe. Poor design and dimension of the suction piping can lead to cavitation in the pump which [...] Read more.

The effective and reliable performance of any pump can be significantly impacted by the piping system design. One of the essential points is the pump suction pipe. Poor design and dimension of the suction piping can lead to cavitation in the pump which affects its head and efficiency. The primary objective is to reduce the hydraulic losses of the suction piping in order to maintain a Net Positive Suction Head required by the pump. Suction piping is recommended to be short and straight, and branch connections, valves and elbows should be avoided, which is not always possible. In addition, cavitation can occur in the actual hydraulic elements installed on the pump suction. This work is focused on the investigation of cavitating hydraulic element in the suction pipe on the pump performance. A converging-diverging nozzle with a circular cross-section was used for this purpose. A straight pipe segment of constant diameter and the same length was used for comparison. Both elements were characterized by the loss coefficient and the cavitation number. Their influence on the pump head and the Net Positive Suction Head Available (NPSHA) was investigated. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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23 pages, 11733 KiB

Open AccessArticle

Life Cycle Cost Analysis of Pumping System through Machine Learning and Hidden Markov Model

by Nabanita Dutta, Kaliannan Palanisamy, Paramasivam Shanmugam, Umashankar Subramaniam and Sivakumar Selvam

Processes 2023, 11(7), 2157; https://doi.org/10.3390/pr11072157 - 19 Jul 2023

Cited by 3 | Viewed by 2194

Abstract

The pumping system is a critical component in various industries and consumes 20% of the world’s energy demand, with 25–50% of that energy used in industrial operations. The primary goal for users of pumping systems is to minimise maintenance costs and energy consumption. [...] Read more.

The pumping system is a critical component in various industries and consumes 20% of the world’s energy demand, with 25–50% of that energy used in industrial operations. The primary goal for users of pumping systems is to minimise maintenance costs and energy consumption. Life cycle cost (LCC) analysis is a valuable tool for achieving this goal while improving energy efficiency and minimising waste. This paper aims to compare the LCC of pumping systems in both healthy and faulty conditions at different flow rates, and to determine the best AI-based machine learning algorithm for minimising costs after fault detection. The novelty of this research is that it will evaluate the performance of different machine learning algorithms, such as the hybrid model support vector machine (SVM) and the hidden Markov model (HMM), based on prediction speed, training time, and accuracy rate. The results of the study indicate that the hybrid SVM-HMM model can predict faults in the early stages more effectively than other algorithms, leading to significant reductions in energy costs. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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14 pages, 17687 KiB

Open AccessArticle

An Investigation on Optimized Performance of Voluteless Centrifugal Fans by a Class and Shape Transformation Function

by Meijun Zhu, Zhehong Li, Guohui Li, Xinxue Ye, Yang Liu, Ziyun Chen and Ning Li

Processes 2023, 11(6), 1751; https://doi.org/10.3390/pr11061751 - 8 Jun 2023

Cited by 1 | Viewed by 1583

Abstract

Class and shape transformation functions are proposed to carry out the parametric design of the blade profiles because fan efficiency is closely related to the shape of blade profiles. An optimization with the objectives of fan efficiency and static pressure based on the [...] Read more.

Class and shape transformation functions are proposed to carry out the parametric design of the blade profiles because fan efficiency is closely related to the shape of blade profiles. An optimization with the objectives of fan efficiency and static pressure based on the Kriging models was established, and numerical simulation data were applied to construct the Kriging models. The dissipation function was used to analyze the fan energy loss. The prediction results show that the maximum accuracy error between the Kriging model and the experimental data is approximately 0.81%. Compared with the prototype fan, the optimized fan was able to ameliorate the distribution of the flow field pressure and velocity; the outlet static pressure increased by 9.03%, and the efficiency increased by 2.35%. The dissipation function is advantageous because it can intuitively indicate the location and amount of energy loss in the fan, while effectively obtaining the total energy loss as well. The situation of energy loss was mutually validated with the density of the static pressure contours and the streamline distribution. The flow fields at the leading edge of the optimized fans were improved by analysis of the dissipation function, and the leading edges of the three impellers selected from the Pareto front were narrower and flatter than those of the prototype fan. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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17 pages, 10488 KiB

Open AccessArticle

The Suppression of Hump Instability inside a Pump Turbine in Pump Mode Using Water Injection Control

by Jun Yang, Xianhua Feng, Xiaohua Liu, Tao Peng, Zhijie Chen and Zihang Wang

Processes 2023, 11(6), 1647; https://doi.org/10.3390/pr11061647 - 28 May 2023

Cited by 5 | Viewed by 1634

Abstract

The occurrence of hump instability in pump mode within a pump turbine poses a significant challenge to the safe and stable operation of Pumped Storage Power Plants (PSPP). To achieve more precise numerical simulations, this paper establishes a weakly compressible model of water [...] Read more.

The occurrence of hump instability in pump mode within a pump turbine poses a significant challenge to the safe and stable operation of Pumped Storage Power Plants (PSPP). To achieve more precise numerical simulations, this paper establishes a weakly compressible model of water based on the Tait equation. Using this model, it is discovered that the onset of hump instability is closely linked to an increase in hydraulic losses induced by stalled rotation within the diffuser. Then, a flow control approach employing water injection into the guide vanes of a pump turbine is proposed in order to suppress flow instabilities and optimize the hump region. The findings reveal that the water injection approach can mitigate hydraulic losses, suppress unstable structures, and diminish the pulsation amplitude within the diffuser, ultimately delaying the emergence of the hump region to lower flow mass conditions. This study is helpful in widening the range of the safe and stable operation of pump turbines in pump mode. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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19 pages, 9073 KiB

Open AccessArticle

Study on the Hydraulic Characteristics of an Eccentric Tapering Outlet Pressure Box Culvert in a Pumping Station

by Ye-Xin Chen, Bin Xi, Zhigang Chen and Shixuan Shen

Processes 2023, 11(6), 1598; https://doi.org/10.3390/pr11061598 - 23 May 2023

Cited by 1 | Viewed by 1202

Abstract

The outlet pressure box culvert is often used as the drainage building of a pumping station. Because of its compact structure, it produces transverse flow velocity and then forms poor flow patterns, such as bias flow, reflux, and flow separation, which affect the [...] Read more.

The outlet pressure box culvert is often used as the drainage building of a pumping station. Because of its compact structure, it produces transverse flow velocity and then forms poor flow patterns, such as bias flow, reflux, and flow separation, which affect the discharge efficiency of the pumping station. Based on the combination of a physical model test and numerical simulation, the hydraulic characteristics of an eccentric tapering outlet pressure box culvert were analyzed. Focusing on the poor flow pattern in the box culvert, different optimization schemes were proposed to adjust the flow pattern. The flow pattern, transverse velocity distribution ratio (which represents the proportion of transverse velocity in velocity), average angle of the axial velocity, axial velocity uniformity, and pressure distribution of each scheme were compared to obtain the best scheme. The results show that the combination scheme of “diversion pier position and angle with deflecting flow baseplate” has the best optimization effect on the flow pattern. This scheme can effectively improve the bad flow pattern, significantly reduce the transverse velocity distribution ratio, and make the pressure distribution on both sides of the long diversion pier uniform. The axial velocity uniformity was increased by 17.45%, and the average angle of the axial velocity was increased by 8.23°. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 44526 KiB

Open AccessArticle

Making a Soft Elastic Pulsation Pump (SEPP)

by Hao Gu, Yun Xia, Yu Zhang and Xiao Dong Chen

Processes 2023, 11(5), 1581; https://doi.org/10.3390/pr11051581 - 22 May 2023

Viewed by 1474

Abstract

In this work, a soft-elastic pulsation pump (SEPP) has been made and investigated. Here, 3D printing was used to make casting molds and a melt-removal method using wax was employed. The SEPP was made of silicone rubber and driven by an external squeezing [...] Read more.

In this work, a soft-elastic pulsation pump (SEPP) has been made and investigated. Here, 3D printing was used to make casting molds and a melt-removal method using wax was employed. The SEPP was made of silicone rubber and driven by an external squeezing mechanism. A silicone one-way valve was also made which prevented backflow after the fluid was squeezed out of the pump chamber. The material characteristics of the SEPP including durability were examined. The pump operating parameters were confirmed to differential pressure of 100 mm Hg in a close flow loop. The average flow rate was 2 L/min, while yielding a peak flow of 8 L/min, and a stroke volume of 70 mL. A preliminary trial using fresh animal blood had shown that the SEPP has good protection on the blood. Therefore, within the resources available, an interesting idea for an effective SEPP has been proposed and realized in the laboratory. The technical details of the SEPP described, and the experimental results reported here form a good basis for making higher capacity SEPPs. This effort may help make its way to an effective ventricular assist device. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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14 pages, 2623 KiB

Open AccessArticle

Experimental Hardware-in-the-Loop Centrifugal Pump Simulator for Laboratory Purposes

by Levon Gevorkov and José Luis Domínguez-García

Processes 2023, 11(4), 1163; https://doi.org/10.3390/pr11041163 - 10 Apr 2023

Cited by 1 | Viewed by 1953

Abstract

A hardware-in-the-loop (HIL) experimental test-bench is suggested for a rotodynamic pump in this paper. The HIL simulator is composed of two separate modules and two variable-speed drive (VSD) systems that are connected with the help of a programmable logical controller (PLC) and a [...] Read more.

A hardware-in-the-loop (HIL) experimental test-bench is suggested for a rotodynamic pump in this paper. The HIL simulator is composed of two separate modules and two variable-speed drive (VSD) systems that are connected with the help of a programmable logical controller (PLC) and a process field bus unit. One of the fundamental components of the suggested simulation approach is the mathematical representation of a rotodynamic pump system embedded into HIL. A number of tests were conducted in order to study the suggested simulation approach. The experiments demonstrated the developed system’s adaptability and precision in replicating the behavior of the rotodynamic pump in various operation modes. A special user interface for the HIL simulation allows for changing the types of preloaded pump characteristics, reading the output data, and controlling operational parameters. The obtained simulation results showed that the proposed approach can be suitable for research purposes. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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21 pages, 9738 KiB

Open AccessArticle

Improving the Modeling of Pressure Pulsation and Cavitation Prediction in a Double-Volute Double-Suction Pump Using Mosaic Meshing Technology

by Virgel M. Arocena and Louis Angelo M. Danao

Processes 2023, 11(3), 660; https://doi.org/10.3390/pr11030660 - 22 Feb 2023

Cited by 8 | Viewed by 2623

Abstract

Over the years, Computational Fluid Dynamics (CFD) has been an integral part of most pump design processes. Unfortunately, as calculation schemes and flow investigations become more complicated, the cost of conducting numerical simulations also becomes more expensive in terms of computational time. To [...] Read more.

Over the years, Computational Fluid Dynamics (CFD) has been an integral part of most pump design processes. Unfortunately, as calculation schemes and flow investigations become more complicated, the cost of conducting numerical simulations also becomes more expensive in terms of computational time. To remedy this, cutting-edge technology, together with novel calculation techniques, are continuously introduced with the end target of producing more accurate results and faster computing time. In this paper, CFD simulations are run on a numerical model of a double-volute double-suction pump prepared using ANSYS Fluent Mosaic meshing technology. Poly-Hexcore, the first application of Mosaic technology, fills the bulk region with octree hexes, keeps a high-quality layered poly-prism mesh in the boundary layer, and conformally connects these two meshes with general polyhedral elements. This technology promises to provide a lower number of cells along with a significant increase in computing speed. In this paper, steady state results of the model with Mosaic Poly-Hexcore mesh with ~37% fewer cells produced comparable results with a similarly sized model prepared with multi-block structured hexagonal mesh. The predicted pump head, efficiency and shaft power under the design conditions were within 1% for both models, while calculation time was reduced by ~25%. Additional simulations using the Poly-Hexcore mesh showed that the model was able to closely predict the pump’s NPSH3 for

0.8 Q_{D}

,

1.0 Q_{D}

, and

1.2 Q_{D}

compared with the manufacturer’s data. Under cavitating flow conditions, the formation of vapor bubbles was observed on the suction side, starting at the leading edge of the blade and slowly forming as thin sheets towards the trailing edge as the suction pressure is reduced. Lastly, pressure fluctuations were observed from pressure coefficient data collected at several monitoring points in the volute and the impeller. It was seen that due to the interaction between the stationary casing and the rotating impeller, pulsations were equivalent to the blade passing frequency and its harmonics. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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20 pages, 8592 KiB

Open AccessArticle

Parametric Analysis and Optimization Design of the Twin-Volute for a New Type of Dishwasher Pump

by Haichao Sun, Hui Xu, Yanjun Li, Xikun Wang and Yalin Li

Processes 2023, 11(2), 305; https://doi.org/10.3390/pr11020305 - 17 Jan 2023

Cited by 1 | Viewed by 1660

Abstract

To improve the hydraulic performance of a new type of dishwasher pump and solve the multi-parameter optimization problem, a genetic algorithm was introduced to optimize the special design of the twin-volute structure. Six curvature radii of the twin-volute structure were defined as the [...] Read more.

To improve the hydraulic performance of a new type of dishwasher pump and solve the multi-parameter optimization problem, a genetic algorithm was introduced to optimize the special design of the twin-volute structure. Six curvature radii of the twin-volute structure were defined as the optimization parameters, and 100 groups of design samples were generated based on the Latin hypercube sampling (LHS) method. The pump head and the efficiency were taken as the optimization objectives, i.e., to improve the efficiency as much as possible while ensuring that the head would not be lower than 2 m. The important parameters were identified via sensitivity analysis, and the optimization problem was solved in detail by using the multi-objective genetic algorithm (MOGA). The results showed that the external profile of the first to the fourth section of the twin-volute structure had the most significant effect on the pump head and efficiency. The response surface method (RSM) was used to select the intervals of optimization, and a comparative simulation of the pump schemes before and after optimization was performed. The head curve did not significantly change before and after optimization. By contrast, the efficiency of the dishwasher pump significantly increased, showing an increase of 2.7% under the design point. Compared with the original model, the impeller of the optimal model pump had a lower overall distribution of turbulent kinetic energy, reduced the vorticity in the twin-volute inlet area, and increased the pressure in the flow channel. Our research results confirm that the combination of RSM and MOGA can effectively solve the problem of optimization for new types of dishwashers and can provide a reference for the development of subsequent hydraulic models. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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19 pages, 5067 KiB

Open AccessArticle

A Systematic Investigation on the Damage Characteristics of Fish in Axial Flow Pumps

by Lufeng Zhu, Fan Zhang, Xiaotao Shi, Kofi Asamoah Adu-Poku, Jinfeng Zhang and Shouqi Yuan

Processes 2022, 10(11), 2228; https://doi.org/10.3390/pr10112228 - 30 Oct 2022

Cited by 3 | Viewed by 1726

Abstract

An axial flow pump is a kind of high-specific revolution vane pump that has the characteristics of large flow, low head, and high efficiency. Due to its unique properties, it is widely used in large water diversion projects, such as the South-to-North Water [...] Read more.

An axial flow pump is a kind of high-specific revolution vane pump that has the characteristics of large flow, low head, and high efficiency. Due to its unique properties, it is widely used in large water diversion projects, such as the South-to-North Water Diversion Project. However, during the operation of the pump, some fish enter the axial flow pump together with the water flow through the screen before the entrance of the pump station. Consequently, some fish are inevitably damaged or even die in the process of traversing through the pump. Meanwhile, the decay of dead fish directly affects the quality of water, hence, posing serious ecological pollution and destabilizing the ecological balance. Therefore, understanding the dynamics of axial flow pumps in relation to fish species in water bodies for biodiversity and ecosystem services remain vital for nature conservation. In this paper, the impact of damage of the model pump on fish is exhaustively investigated according to the theory of blade impact model, impact probability, impact mortality, and mortality distribution under different working conditions. Through the simulation of the flow state inside the impeller, the areas that are lower than the pressure threshold, higher than the shear strain rate threshold, and higher than the pressure gradient threshold in the impeller at different flow rates are analyzed. Based on the unsteady results, the volume fluctuation characteristics of the three damage mechanisms in the impeller are analyzed. Furthermore, Powell vortex acoustic equation is used to locate the high noise source region of the axial flow pump. After extensive comparison of the dipole sound source intensity, it is revealed that the dipole noise source in the impeller and guide vane is dominant. In conclusion, this study provides a holistic perspective for evaluating fish damage caused by the flow in the impeller of the axial flow pump. Furthermore, it will proffer significant references to the construction of ecological water conservancy projects. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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18 pages, 7137 KiB

Open AccessArticle

Analysis of the Influence of Structure and Parameters of Axial Piston Pump on Flow Pulsation

by Ruichuan Li, Qi Liu, Yi Cheng, Jilu Liu, Qiyou Sun, Yisheng Zhang and Yurong Chi

Processes 2022, 10(10), 2138; https://doi.org/10.3390/pr10102138 - 20 Oct 2022

Cited by 5 | Viewed by 4084

Abstract

In view of the working principle of a swashplate axial piston pump, a simulation model of the piston pump was built in AMESim and its output flow pulsation characteristics were simulated and analyzed. We mainly analyzed the influence of the speed of the [...] Read more.

In view of the working principle of a swashplate axial piston pump, a simulation model of the piston pump was built in AMESim and its output flow pulsation characteristics were simulated and analyzed. We mainly analyzed the influence of the speed of the prime mover, the swashplate angle, the diameter of the piston, and port plate structure on the flow pulsation of the piston pump. The result of this research shows that the port plate structure, the swashplate angle, and the speed of the prime mover have an important influence on the flow pulsation of the piston pump. In order to effectively reduce the flow pulsation generated by the piston pump and reduce the noise generated in the process of flow distribution, the opening of the pre-compression angle and misalignment angle of the port plate of the piston pump must be reduced appropriately and the swashplate angle and the rotation speed of the prime mover should be controlled within a certain range. The flow pulsation of the axial piston pump decreases with the increase of the piston number and the decrease in the misalignment angle. The research results provide a reference for reducing the flow pulsation of the axial piston pump. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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17 pages, 6273 KiB

Open AccessArticle

Boundary Layer Transition Prediction on Planar Turbine Cascade Using Temperature-Sensitive Paint and Numerical Simulation

by Wenliang Ke, Hongbiao Wang, Wenwu Zhang, Kang Huang and Baoshan Zhu

Processes 2022, 10(10), 2078; https://doi.org/10.3390/pr10102078 - 14 Oct 2022

Viewed by 1380

Abstract

Advanced measurement technology on boundary layer transition is an effective means to study the flow mechanism and the performance of the cascade. In this research, to investigate the boundary layer transition of transonic VKI-RG turbine cascade, a noncontact measurement technique named temperature-sensitive paint [...] Read more.

Advanced measurement technology on boundary layer transition is an effective means to study the flow mechanism and the performance of the cascade. In this research, to investigate the boundary layer transition of transonic VKI-RG turbine cascade, a noncontact measurement technique named temperature-sensitive paint (TSP) that is capable of quantitatively measuring the surface temperature of a model is used. Under the conditions of outlet Mach number (Ma₂) = 0.4, 1.03, and 1.2, the transitional location of a cascade is accurately measured by TSP technique. Moreover, a numerical study on the transitional location of a planar cascade was conducted with the conditions of Mach number (Ma) and attack angle (α). The numerical results show that the transitional location moved forward with the increase in Ma₂ and α at Ma₂ < 1; otherwise, the transitional location moved backward with increasing Ma₂ (Ma₂ > 1). Lastly, a strong adverse pressure gradient was formed behind the shock wave, which led to the beginning of the transition. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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21 pages, 8567 KiB

Open AccessArticle

Orthogonal Optimization Design of the Compound Impeller for a New Type of Dishwasher Pump

by Yanjun Li, Haichao Sun, Hui Xu, Xikun Wang and Yalin Li

Processes 2022, 10(9), 1813; https://doi.org/10.3390/pr10091813 - 8 Sep 2022

Cited by 1 | Viewed by 2112

Abstract

A new type of dishwasher pump without a pipeline system was invented for the first time to form an original sink-type dishwasher avoiding the accumulation of dirt in the hydraulic system. In order to improve the hydraulic performance of this new type of [...] Read more.

A new type of dishwasher pump without a pipeline system was invented for the first time to form an original sink-type dishwasher avoiding the accumulation of dirt in the hydraulic system. In order to improve the hydraulic performance of this new type of dishwasher pump with twin-volute passive rotation driven by a compound impeller, an orthogonal optimal design method was first introduced to optimize the compound impeller composed of axial cascades and radial blades. Six geometric parameters were selected as the main factors to design the orthogonal table L₁₈(3⁶). All impeller models were manufactured via high-precision 3D printing and tested to determine the optimal solution. Firstly, the hydraulic performance was measured using a specially designed test bench under the assumption of static-volute conditions. Then, the optimization scheme was verified in real machine experiments under the rotating-volute condition, and numerical calculations were used to assess the performance improvement due to optimization under the static- and rotating-volute conditions. The results show that the main factors affecting the pump head and efficiency are impeller outlet diameter D₂ and profile line L. The optimized pump head and efficiency are significantly higher than those of the original scheme. Furthermore, the entropy production of each flow passage component of this new type of dishwasher pump is significantly reduced after optimization. Under the static-volute condition, the scheme obtained using the range analysis displays an increase of 0.3 m in the pump head and 2.99% in pump efficiency. Under the rotating-volute condition, the optimization scheme is also effective (pump head increased by 0.54 m, and pump efficiency by 7.46%). At the same time, the passive rotation speed of the twin-volute increases from 60 rpm to 70 rpm, verifying that both the optimization method is reliable and can be used when developing and optimizing dishwasher pumps. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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18 pages, 7876 KiB

Open AccessArticle

Flow Characteristics and Optimization Design of the Stator–Rotor Cavity of the Full Tubular Pump

by Lijian Shi, Jun Zhu, Jindong Li, Fangping Tang, Beishuai Chen, Yuhang Jiang, Tian Xu and Yao Chai

Processes 2022, 10(9), 1688; https://doi.org/10.3390/pr10091688 - 25 Aug 2022

Cited by 2 | Viewed by 1647

Abstract

The full tubular pump device is taken as the research object in this article. This research method adopts the numerical simulation technology based on the SST (Shear-Stress-Transport) k-ω turbulence model to explore the internal flow characteristics of the stator–rotor cavity of the full [...] Read more.

The full tubular pump device is taken as the research object in this article. This research method adopts the numerical simulation technology based on the SST (Shear-Stress-Transport) k-ω turbulence model to explore the internal flow characteristics of the stator–rotor cavity of the full tubular pump and optimize the stator–rotor clearance structure. The research shows that under the design conditions, compared with the axial flow pump, the torque increases by 47.91 N·m at the stator–rotor cavity structure and the efficiency decreases by about 20%. The torque at the rotor clearance of the full tubular pump accounts for about 50% of the torque at the rotor. Since there is a large area of backflow on both sides of the cavity, and there is a vortex structure on the inlet side of the cavity, it shows that the rotor structure and its area greatly affect the operating efficiency of the pump device. With the reduction in the rotor force area, the clearance length, and the outer diameter of the disc, the operating efficiency of the pump device gradually increases. Under the design conditions, the optimized model has a maximum efficiency increase of 14.04% and the torque at the cavity rotor is reduced by 39.25 N·m. The results show that the operating efficiency of the full tubular pump is closely related to its rotor structure area, and the force area of the rotor structure needs to be controlled in the actual design process. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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23 pages, 11190 KiB

Open AccessArticle

Effects of a Detached Eddy Simulation-Curvature Correction (DES-CC) Turbulence Model on the Unsteady Flows of Side Channel Pumps

by Runshi Liu, Fan Zhang, Ke Chen, Yefang Wang, Shouqi Yuan and Ruihong Xu

Processes 2022, 10(8), 1630; https://doi.org/10.3390/pr10081630 - 17 Aug 2022

Cited by 2 | Viewed by 1822

Abstract

A side channel pump is a pump with a high head and a small flow that is widely used in various industrial fields. Many scientists have studied the hydraulic performance, pressure fluctuation characteristics, and gas-liquid mixed transport characteristics of this type of pump. [...] Read more.

A side channel pump is a pump with a high head and a small flow that is widely used in various industrial fields. Many scientists have studied the hydraulic performance, pressure fluctuation characteristics, and gas-liquid mixed transport characteristics of this type of pump. However, these studies mainly focused on the single-stage impeller of the side channel pump, without considering the inter-stage connection channel and the multistage timing effect. These characteristics affect the hydraulic performance and pressure-pulsation characteristics of the side channel pump. Therefore, we carried out a numerical simulation and an experimental comparison on the multistage side channel pump to explore its flow characteristics during the stages. This study focused on the influence of different turbulence models on the numerical simulation of multistage side channel pumps. Shear stress transport (SST), detached eddy simulation (DES), and detached eddy simulation-curvature correction (DES-CC) turbulence models were selected for consideration. By studying the pressure and velocity streamline distribution, the turbulent kinetic energy, and the shape and volume of the vortex core area simulated by the three models, we concluded that the DES-CC model, when compared to the other models, can more fully reflect the vortex characteristics and the simulation results that are closer to the experimental data. The results of this study can be used as the basis for future research on multistage side channel pumps. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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16 pages, 7585 KiB

Open AccessFeature PaperArticle

Introducing Non-Hierarchical RSM and MIGA for Performance Prediction and Optimization of a Centrifugal Pump under the Nominal Condition

by Wenjie Wang, Ju Sun, Jun Liu, Jiantao Zhao, Ji Pei and Jiabin Wang

Processes 2022, 10(8), 1529; https://doi.org/10.3390/pr10081529 - 4 Aug 2022

Cited by 1 | Viewed by 1761

Abstract

In order to improve the operation performance of the multi-stage double-suction centrifugal pump and reduce the internal energy loss of the pump, this paper proposes a single-objective optimization design method based on the non-hierarchical response surface methodology (RSM) and the multi-island genetic algorithm [...] Read more.

In order to improve the operation performance of the multi-stage double-suction centrifugal pump and reduce the internal energy loss of the pump, this paper proposes a single-objective optimization design method based on the non-hierarchical response surface methodology (RSM) and the multi-island genetic algorithm (MIGA). Nine parameters, such as the blade outlet width and blade wrap angle, were used as design variables, and the optimization objective was efficiency under design conditions. In total, 149 sets of valid data were obtained under the Latin hypercube sampling method (LHS), the corresponding thresholds were set for efficiency and head, and 99 sets of valid data were obtained. A cross-validation analysis of the sieved data was carried out based on non-hierarchical RSM, global optimization of the efficiency was carried out using MIGA, and numerical verification was carried out via CFD. The research results show that compared with hierarchical RSM, non-hierarchical RSM can approximate the nonlinear relationship between the objective function and the design variables with higher accuracy, and the model fitting R² value was 0.919. The efficiency was improved by 3.717% after optimization. The overall prewhirl of the impeller inlet after optimization decreased, the internal speed of the volute significantly improved, the large-area vortex at the volute and the outlet pipe was eliminated, the impact loss at the volute separating tongue disappeared, and the overall hydraulic performance of the pump was improved. The total entropy output value of the optimized pump was reduced by 4.79 (W/K), mainly concentrated on the reduction in the entropy output value of the double volute, and the overall energy dissipation of the pump was reduced. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 5341 KiB

Open AccessArticle

Laser Doppler Velocimetry Test of Flow Characteristics in Draft Tube of Model Pump Turbine

by Wanquan Deng, Zhen Li, Lei Ji, Linmin Shang, Demin Liu and Xiaobing Liu

Processes 2022, 10(7), 1323; https://doi.org/10.3390/pr10071323 - 6 Jul 2022

Cited by 7 | Viewed by 2160

Abstract

For Francis pump turbines, the pressure pulsation characteristics of the draft tube are some of the key concerns during the operation of the units. The pressure pulsation characteristics of the draft tube are directly related to the draft tube spiral cavitating vortex rope. [...] Read more.

For Francis pump turbines, the pressure pulsation characteristics of the draft tube are some of the key concerns during the operation of the units. The pressure pulsation characteristics of the draft tube are directly related to the draft tube spiral cavitating vortex rope. In this paper, the velocity distribution in the draft tube of a Francis pump turbine is tested by means of laser Doppler velocimetry. The velocity pulsation was found to be directly related to the pressure pulsation, while the velocity pulsation was also influenced by the cavitation coefficient. The main frequency of the velocity pulsation was close to the main frequency of the pressure pulsation and became larger as the cavitation factor increased. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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25 pages, 6848 KiB

Open AccessFeature PaperArticle

Design and Optimization of γ-Shaped Settlement Training Wall Based on Numerical Simulation and CCD-Response Surface Method

by Bo Xu, Jianfeng Liu, Weigang Lu, Lei Xu and Renyi Xu

Processes 2022, 10(6), 1201; https://doi.org/10.3390/pr10061201 - 17 Jun 2022

Cited by 4 | Viewed by 1789

Abstract

To ameliorate the inflow state of the joint hub of a pump station and sluice, a γ-shaped settlement training wall was designed with its state adjusted automatically in line with the actual working condition of the project. The central composite design (CCD) of [...] Read more.

To ameliorate the inflow state of the joint hub of a pump station and sluice, a γ-shaped settlement training wall was designed with its state adjusted automatically in line with the actual working condition of the project. The central composite design (CCD) of the response surface method was adopted to optimize the geometrical size of the training wall in the operational states of pumping and free-draining separately. The results showed that the alteration of different size factors of the γ-shaped settlement training wall had different degrees of influence on its rectification effect; the intake flow state of the joint hub of the sluice and pumping station with the γ-shaped settlement training wall can be significantly improved with the flow velocity uniformity in the inlet channel next to the junction of the sluice chamber, reaching 80.42%, and the flow velocity uniformity ahead of the sluice, reaching 84.78%, in the operational state of free-draining. By combining the results of numerical simulation, the feasibility of the response surface method was further verified and the optimal combination of geometric parameters of the γ-shaped settlement training wall were also obtained, which can be adopted in the design of the actual joint hub of the pump station and sluice. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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12 pages, 3345 KiB

Open AccessArticle

Investigation on Vibration Signal Characteristics in a Centrifugal Pump Using EMD-LS-MFDFA

by Xing Liang, Yuanxing Luo, Fei Deng and Yan Li

Processes 2022, 10(6), 1169; https://doi.org/10.3390/pr10061169 - 10 Jun 2022

Cited by 5 | Viewed by 1846

Abstract

Vibration signals from centrifugal pumps are nonlinear, non-smooth, and possess implied trend terms, which makes it difficult for traditional signal processing methods to accurately extract their fault characteristics and details. With a view to rectifying this, we introduced empirical mode decomposition (EMD) to [...] Read more.

Vibration signals from centrifugal pumps are nonlinear, non-smooth, and possess implied trend terms, which makes it difficult for traditional signal processing methods to accurately extract their fault characteristics and details. With a view to rectifying this, we introduced empirical mode decomposition (EMD) to extract the trend term signals. These were then refit using the least squares (LS) method. The result (EMD-LS) was then combined with multi-fractal theory to form a new signal identification method (EMD-LS-MFDFA), whose accuracy was verified with a binomial multi-fractal sequence (BMS). Then, based on the centrifugal pump test platform, the vibration signals of shell failures under different degrees of cavitation and separate states of loosened foot bolts were collected. The signals’ multi-fractal spectra parameters were analyzed using the EMD-LS-MFDFA method, from which five spectral parameters (

Δ α

,

Δ f

,

α_{0}

,

α_{\max}

, and

α_{\min}

) were extracted for comparison and analysis. The results showed EMD-LS-MFDFA’s performance was closer to the BMS theoretical value than that of MFDFA, displayed high accuracy, and was fully capable of revealing the multiple fractal characteristics of the centrifugal pump fault vibration signal. Additionally, the mean values of the five types of multi-fractal spectral characteristic parameters it extracted were much greater than the normal state values. This indicates that the parameters could effectively distinguish the normal state and fault state of the centrifugal pump. Moreover,

α_{0}

and

α_{\max}

had a smaller mean square than

Δ α

,

Δ f

and

α_{\min}

, and their stability was higher. Thus, compared to the feature parameters extracted by MFDFA, our method could better realize the separation between the normal state, cavitation (whether slight, moderate, or severe), and when the anchor bolt was loose. This can be used to characterize centrifugal pump failure, quantify and characterize a pump’s different working states, and provide a meaningful reference for the diagnosis and study of pump faults. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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20 pages, 8517 KiB

Open AccessArticle

Study on the Influence of Flow Distribution Structure of Piston Pump on the Output of Pulsation Pump

by Ruichuan Li, Jilu Liu, Xinkai Ding and Qi Liu

Processes 2022, 10(6), 1077; https://doi.org/10.3390/pr10061077 - 27 May 2022

Cited by 5 | Viewed by 2851

Abstract

According to the working principle of the A10VNO swashplate axial piston pump, the output flow model of an axial piston pump in an ideal state and the output flow theoretical model of an axial piston pump considering the leakage and flow distribution process [...] Read more.

According to the working principle of the A10VNO swashplate axial piston pump, the output flow model of an axial piston pump in an ideal state and the output flow theoretical model of an axial piston pump considering the leakage and flow distribution process are established. The output flow pulsations of odd and even piston pumps are simulated and analyzed by Matlab, and the influence of a closed dead angle and a mismatch angle of the port plate on the output flow pulsation of the pump is obtained. Based on the theoretical model, AMESim is used to establish the overall model of the axial piston pump considering leakage, flow distribution process and oil compressibility under constant working conditions. By setting six different flow distribution boundary conditions corresponding to the theoretical research, the influence of flow distribution plate structure on pump output flow pulsation is studied. A test-bed was built and verified by experiments. The results show that when the mismatch angle of the valve plate is 3–5° and the dead angle is 6–10°, the difference between the output flow pulsations of the odd and even piston pumps is very small, so in the hydraulic pump hydraulic motor system, when the hydraulic pump is used as a hydraulic motor under the condition of power recovery, the odd number or adjacent even number of hydraulic motors are appropriate. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 4421 KiB

Open AccessArticle

Performance Optimization on 3D Diffuser of Volute Pump Using Kriging Model

by Zhenhua Han, Wenjie Wang, Congbing Huang and Ji Pei

Processes 2022, 10(6), 1076; https://doi.org/10.3390/pr10061076 - 27 May 2022

Viewed by 1947

Abstract

In order to enhance the hydraulic performance of the volute pump, the Kriging model and genetic algorithm (GA) were used to optimize the 3D diffuser of the volute pump, and the hydraulic performance of the optimized model was compared and analyzed with the [...] Read more.

In order to enhance the hydraulic performance of the volute pump, the Kriging model and genetic algorithm (GA) were used to optimize the 3D diffuser of the volute pump, and the hydraulic performance of the optimized model was compared and analyzed with the original model. The volute pump diffuser model was parameterized by BladeGen software. A total of 14 parameters such as the distance between the leading and trailing edges and the central axis, and the inlet and outlet vane angle were selected as design variables, and the efficiency under the design condition was taken as the optimization objective. A total of 70 sets of sample data were randomly selected in the design space to train and test the Kriging model. The optimal solution was obtained by GA. The shape and inner flow of the optimized diffuser were compared with those of the original diffuser. The research results showed that the Kriging model can effectively establish the high-precision mathematical function between the design variables and the optimization objective, and the R² value is 0.95356, which meets the engineering needs. The optimized geometry model demonstrated a significant change, the vane leading edge became thinner, and the wrap angle increased. After optimization, the hydraulic performance of the volute pump under design and part-load conditions were greatly improved, the efficiency under design conditions increased by 2.65%, and the head increased by 0.83 m. Furthermore, the inner flow condition improved, the large area of low-speed and vortex disappeared, the pressure distribution in the diffuser was more reasonable, and the pressure gradient variation decreased. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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18 pages, 13305 KiB

Open AccessArticle

Hydraulic Optimization of Closed Transformation of Open Sump for the Water Treatment Pumping Station

by Xuanda Cheng and Xin Chen

Processes 2022, 10(4), 644; https://doi.org/10.3390/pr10040644 - 25 Mar 2022

Viewed by 2087

Abstract

Taking the closed modification of an open sump of a water treatment pump station as the research background, the hydraulic design criteria for the closed modification of the sump are put forward by combining numerical simulation, model test. Based on CFD technology, a [...] Read more.

Taking the closed modification of an open sump of a water treatment pump station as the research background, the hydraulic design criteria for the closed modification of the sump are put forward by combining numerical simulation, model test. Based on CFD technology, a water pumping station including closed sump, bellmouth, impeller, guide vane, elbow and outlet sump is simulated, and the hydraulic performance of the schemes under different parameters is analyzed and compared. The top floor clearance, width, back wall distance, and floor clearance of the sump are optimized hydraulically, and the hydraulic design criteria of the closed sump are obtained. The results show that when the recommended optimization parameters of the closed sump in this study are that the top floor height H_D is 0.9 D_L, the width B is 3.0 D_L, the back wall distance T is from 0.4 D_L, and the floor clearance C is 0.75 D_L_, the internal flow pattern and hydraulic of the closed sump is better. (D_L is the diameter of bellmouth of water pumping station). The model test was set up to compare the hydraulic performance of the pumping station between CFD and the test. The results showed that the CFD data is in good agreement with the experimental data. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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13 pages, 6617 KiB

Open AccessArticle

Effects of the Balance Hole Diameter on the Flow Characteristics of the Rear Chamber and the Disk Friction Loss in the Centrifugal Pump

by Wei Dong, Ze Liu, Haichen Zhang, Guang Zhang, Haoqing Jiang and Peixuan Li

Processes 2022, 10(3), 613; https://doi.org/10.3390/pr10030613 - 21 Mar 2022

Cited by 4 | Viewed by 2762

Abstract

This paper studies the flow characteristics and disk friction loss of the rear chamber in a centrifugal pump at a design flow condition with six values of the balance holes at diameters from 0 to 12 mm. The results show that the turbulent [...] Read more.

This paper studies the flow characteristics and disk friction loss of the rear chamber in a centrifugal pump at a design flow condition with six values of the balance holes at diameters from 0 to 12 mm. The results show that the turbulent boundary layer in the rear chamber is greatly affected by the leakage flow. When the balance hole diameter increases, the flow characteristics of the rear chamber is mainly restricted by the mainstream flow field of the volute. However, when the balance hole diameter is larger than the design value, the disk friction loss of the rear chamber remains basically unchanged. On the contrary, when the balance hole diameter is smaller than the design value, the larger the balance hole diameter the smaller the friction loss of the disk in the rear chamber area. The results of this paper provide a reference for reducing axial force and stable operation of a centrifugal pump. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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12 pages, 2621 KiB

Open AccessArticle

Experiment on Influence of Blade Angle on Hydraulic Characteristics of the Shaft Tubular Pumping Device

by Kaihua Cheng, Songbai Li, Li Cheng, Tao Sun, Bowen Zhang and Weixuan Jiao

Processes 2022, 10(3), 590; https://doi.org/10.3390/pr10030590 - 17 Mar 2022

Cited by 7 | Viewed by 2128

Abstract

In order to understand the influence of blade angle on the hydraulic characteristics of a shaft tubular pumping device, the energy characteristics, cavitation characteristics, runaway characteristics, and pressure pulsation of the tubular pumping device under different blade angles were studied by a model [...] Read more.

In order to understand the influence of blade angle on the hydraulic characteristics of a shaft tubular pumping device, the energy characteristics, cavitation characteristics, runaway characteristics, and pressure pulsation of the tubular pumping device under different blade angles were studied by a model test. Comparing the efficiency of the best efficiency point of the pumping device under different blade angles, it can be seen that when the blade angle is +4°, the efficiency of the best efficiency point of the pumping device is the lowest, 74.10%. When the blade angle is −4°, the efficiency of the best efficiency point of the pumping device is the highest, 79.75%. Comparing the cavitation characteristics of the pumping device under different blade angles, it can be seen that when the blade angle is −4°, the overall cavitation performance of the pumping device is the best. When the design head point is deviated, the NPSH_av (Net positive suction head available) of the pump will increase. At the same blade angle, the runaway speed increases with the increase in head. The runaway speed of the prototype pump decreases with the increase in blade angle. When the blade angle is −6°, the runaway speed of the prototype pump is the largest, which is not conducive to the safe operation of the pumping station. When the blade angle is −4°, the variation law of pressure pulsation is small, and there is no abnormal pulsation. The tubular pumping device has satisfactory hydraulic performance, high efficiency, cavitation, and runaway characteristics. Therefore, the shaft tubular pumping device has wide application prospects under ultra-low head, and we recommend prioritizing it in low-head pumping stations. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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21 pages, 18769 KiB

Open AccessArticle

The Effect of Airfoil Camber on Pressure Fluctuation in Bidirectional Axial-Flow Pump

by Fan Meng, Yanjun Li, Jia Chen, Lei Xu and Yalin Li

Processes 2022, 10(3), 468; https://doi.org/10.3390/pr10030468 - 25 Feb 2022

Viewed by 1821

Abstract

To obtain the influence of airfoil camber on the internal pressure fluctuation of a bidirectional axial-flow pump, the unsteady Reynolds time-averaged Navier–Stokes (URANS) equation was solved to predict the internal flow structure under three airfoil camber cases. The airfoil camber was quantitatively controlled [...] Read more.

To obtain the influence of airfoil camber on the internal pressure fluctuation of a bidirectional axial-flow pump, the unsteady Reynolds time-averaged Navier–Stokes (URANS) equation was solved to predict the internal flow structure under three airfoil camber cases. The airfoil camber was quantitatively controlled by airfoil camber angle. The pressure standard deviation was used to define the local pressure fluctuation intensity (PFI) inside the impeller and guide vane. Fast Fourier transform was applied to analyze the frequency-domain characteristics of the pressure signal near the impeller–straight pipe interface and impeller–guide vanes interface. The results were validated by the external characteristic test. Under the forward condition, the area of high PFI near the outlet and leading edge of the impeller increased with a decrease in airfoil camber angle, and that near the leading edge of the guide vanes shifted to the middle section with a decrease in airfoil camber angle. The main frequency of the pressure signal near the impeller–guide vanes interface was the blade-passing frequency (BPF), and the main frequency amplitude increased with a decrease in airfoil camber angle. Under the reverse condition, the high PFI area near the inlet and the leading edge of the impeller declined with the decrease in airfoil camber angle. The main frequency of the pressure signal near the impeller–straight pipe interface and impeller–guide vanes interface was the BPF, and the main frequency amplitude decreased with a decrease in airfoil camber angle. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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17 pages, 8544 KiB

Open AccessArticle

Hydrodynamic Behavior of a Pump as Turbine under Transient Flow Conditions

by Jianxin Hu, Xianghui Su, Xin Huang, Kexin Wu, Yuzhen Jin, Chunguang Chen and Xulai Chen

Processes 2022, 10(2), 408; https://doi.org/10.3390/pr10020408 - 19 Feb 2022

Cited by 10 | Viewed by 2920

Abstract

Centrifugal pumps as turbines (PATs) are widely used in chemical engineering for recycling the abundant energy from high-pressure fluid. The operation of PATs is significantly affected by their upstream conditions, which are not steady (i.e., with a constant flow rate) in reality, thus, [...] Read more.

Centrifugal pumps as turbines (PATs) are widely used in chemical engineering for recycling the abundant energy from high-pressure fluid. The operation of PATs is significantly affected by their upstream conditions, which are not steady (i.e., with a constant flow rate) in reality, thus, research on the flow mechanism of PATs under transient conditions should be considered of higher importance. In this study, a numerical model of a PAT was developed by employing the sliding mesh method to describe turbine rotation, and a user-defined function (UDF) for characterizing transient flow conditions. Corresponding experiments were also conducted to provide validation results for the simulation, and the simulation results agreed well with the experimental outcomes. The instantaneous characteristic curves under the current working conditions were obtained for different transient flow rates. The results show that the turbine’s efficiency is significantly affected by transient flow conditions. In particular, a rapid increase (large time derivative) of flow rate results in a large energy dissipation at the turbine outlet, and therefore, the turbine efficiency decreases. In addition, as the flow rate increases, the hydrodynamic force on the impeller, and the pressure fluctuation amplitude in the volute first decrease and then increase, reaching the minimum near the design flow rate. The current study provides a reliable and precise approach for the estimation of hydrodynamic performance of fluid machinery under transient flow conditions. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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21 pages, 16718 KiB

Open AccessFeature PaperArticle

The Influence of a Pumping Chamber on Hydraulic Losses in a Mixed-Flow Pump

by Huiyan Zhang, Fan Meng, Lei Cao, Yanjun Li and Xinkun Wang

Processes 2022, 10(2), 407; https://doi.org/10.3390/pr10020407 - 19 Feb 2022

Cited by 5 | Viewed by 2103

Abstract

In this study, entropy generation theory based on computational fluid dynamics (CFD) is used to study the influence of a pumping chamber type (guide vane and volute scheme) on the spatial distribution of hydraulic loss in a mixed-flow pump. The CFD data of [...] Read more.

In this study, entropy generation theory based on computational fluid dynamics (CFD) is used to study the influence of a pumping chamber type (guide vane and volute scheme) on the spatial distribution of hydraulic loss in a mixed-flow pump. The CFD data of the mixed-flow pump with a volute is validated by external characteristic test data under Q = 561.4–1598.6 m³/h. The results show that the efficiency and the head of the guide vanes scheme are lower under Q = 800–1200 m³/h, which resulted from a higher total entropy production (TEP) in the pumping chamber and outlet pipe. The high total entropy production rate (TEPR) inside the guide vanes can be found near the leading edge of the hub side and trailing edge of the rim side due to flow separation, which reduces the recovery efficiency of kinetic energy of the guide vanes. The high TEPR inside outlet pipe can be seen near the inlet, caused by back flow. However, the efficiency and head of the volute scheme are lower, under Q = 1200–1600 m³/h, owing to the fact that the volute cannot effectively convert kinetic energy into pressure energy and thus the high TEPR can be found near outlet of volute and inlet of outlet pipe. These results can provide useful suggestions to the matching optimization of the impeller and pumping chamber in a mixed-flow pump. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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20 pages, 73855 KiB

Open AccessArticle

Influence of Blade Angle Deviation on the Hydraulic Performance and Structural Characteristics of S-Type Front Shaft Extension Tubular Pump Device

by Lijian Shi, Changxin Wu, Li Wang, Tian Xu, Yuhang Jiang, Yao Chai and Jun Zhu

Processes 2022, 10(2), 328; https://doi.org/10.3390/pr10020328 - 8 Feb 2022

Cited by 5 | Viewed by 1770

Abstract

When the axial-flow pump is running, the blade angle is not fully adjusted or there are errors in the manufacture of the blades, which will lead to inconsistent blade placement angles during operation, and which will reduce the efficiency of the axial-flow pump. [...] Read more.

When the axial-flow pump is running, the blade angle is not fully adjusted or there are errors in the manufacture of the blades, which will lead to inconsistent blade placement angles during operation, and which will reduce the efficiency of the axial-flow pump. This paper uses the research methods of numerical simulation and model experiments to analyze the hydraulic performance and impeller structure characteristics of each flow components under different schemes when the angles of each blade of the S-type front shaft extension tubular pump device are inconsistent. The research phenomenon is that the guide vane greatly recovers the flow velocity circulation at the impeller outlet, reduces the hydraulic loss of guide vane, and widens the best efficiency range with an increase in guide vane blade angle. When the blade angle deviation occurs, the flow field of each blade channel affects each other, and the maximum decrease in the best efficiency is up to 7.78%, mainly due to the increased hydraulic loss in the outlet channel. The blade angle deviation will also affect the maximum equivalent stress and maximum deformation of the impeller, which is more obvious in large flow conditions. Inconsistent blade angles seriously affect the operating efficiency of the water pump and water pump device, and make the structural characteristics of the impeller worse. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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15 pages, 10959 KiB

Open AccessArticle

Pressure Fluctuation Characteristics of High-Speed Centrifugal Pump with Enlarged Flow Design

by Jianyi Zhang, Hao Yang, Haibing Liu, Liang Xu and Yuwei Lv

Processes 2021, 9(12), 2261; https://doi.org/10.3390/pr9122261 - 15 Dec 2021

Cited by 11 | Viewed by 3471

Abstract

The pressure fluctuations of high-speed centrifugal pumps are the hotspot in pump research. Pressure fluctuations is differ for different structural designs and flow structures. High-speed centrifugal pumps are usually designed to increase efficiency with an enlarged flow design at a low specific speed, [...] Read more.

The pressure fluctuations of high-speed centrifugal pumps are the hotspot in pump research. Pressure fluctuations is differ for different structural designs and flow structures. High-speed centrifugal pumps are usually designed to increase efficiency with an enlarged flow design at a low specific speed, which changes the structure of the pump. In order to analyze the pressure fluctuations of a high-speed centrifugal pump with an enlarged flow design, the pressure was measured, and the flow field of the pump was simulated with different flow rates. Through analysis, we found that pressure fluctuations varied periodically and was consistent with the blade frequency. The pressure fluctuations at the guide vane and the interference region were also closely related to the vortices at the impeller outlet, which changed differently at different flow rates. The results showed that the high-speed centrifugal pump with an enlarged design had better performance at a large flow rate. The results in this paper can provide reference for the design of a pump that should be designed with the enlarged flow method. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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Review

Jump to: Research

21 pages, 3898 KiB

Open AccessReview

A Review of Pump Cavitation Fault Detection Methods Based on Different Signals

by Xiaohui Liu, Jiegang Mou, Xin Xu, Zhi Qiu and Buyu Dong

Processes 2023, 11(7), 2007; https://doi.org/10.3390/pr11072007 - 4 Jul 2023

Cited by 5 | Viewed by 3488

Abstract

As one of the research hotspots in the field of pumps, cavitation detection plays an important role in equipment maintenance and cost-saving. Based on this, this paper analyzes detection methods of cavitation faults based on different signals, including vibration signals, acoustic emission signals, [...] Read more.

As one of the research hotspots in the field of pumps, cavitation detection plays an important role in equipment maintenance and cost-saving. Based on this, this paper analyzes detection methods of cavitation faults based on different signals, including vibration signals, acoustic emission signals, noise signals, and pressure pulsation signals. First, the principle of each detection method is introduced. Then, the research status of the four detection methods is summarized from the aspects of cavitation-induced signal characteristics, signal processing methods, feature extraction, intelligent algorithm identification of cavitation state, detection efficiency, and measurement point distribution position. Among these methods, we focus on the most widely used one, the vibration method. The advantages and disadvantages of various detection methods are analyzed and proposed: acoustic methods including noise and acoustic emission can detect early cavitation very well; the vibration method is usually chosen first due to its universality; the anti-interference ability of the pressure pulsation method is relatively strong. Finally, the development trend of detecting cavitation faults based on signals is given: continue to optimize the existing detection methods; intelligent algorithms such as reinforcement learning and deep reinforcement learning will be gradually integrated into the field of cavitation status identification in the future; detection systems still need to be further improved to accommodate different types of pumps; advanced sensing devices combined with advanced signal processing techniques are one of the effective means to detect cavitation in a timely manner; draw on other fault detection methods such as bearing faults and motor faults. Full article

(This article belongs to the Special Issue Design and Optimization Method of Pumps)

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