Aerospace

Research

25 pages, 4194 KiB

Open AccessArticle

Development of Carbon Composite Blades within the Context of the Experimental Validation of a CFD-Based Design Tool for Contra-Rotating, Electric Fan Engines

by Sebastian Hawner, Lukas Rduch, Henry Baumhöfener and Andreas Hupfer

Aerospace 2024, 11(7), 527; https://doi.org/10.3390/aerospace11070527 - 27 Jun 2024

Viewed by 994

Abstract

Electric propulsion systems have emerged as a disruptive technological approach towards achieving sustainable and climate-neutral aviation. To expand the operational envelope of such propulsion units in terms of altitude and velocity, an enclosing duct and counter-rotating rotors to enhance efficiency can be utilized. [...] Read more.

Electric propulsion systems have emerged as a disruptive technological approach towards achieving sustainable and climate-neutral aviation. To expand the operational envelope of such propulsion units in terms of altitude and velocity, an enclosing duct and counter-rotating rotors to enhance efficiency can be utilized. In this study, an iterative CFD-based design tool developed for these novel propulsion systems is utilized to design a reference engine, having a classic rotor–stator configuration. Being the key component of this propulsor, a manufacturing process for composite blades is presented. This effort aims to make state-of-the-art technology accessible to smaller research projects, promoting the widespread adoption of electric propulsion technology in the aviation sector. By experimental investigations of the blade elongation both in tensile tests and engine operation, measuring the tip clearance with a high-speed camera, this process could be validated to facilitate the transferability of research. Finally, the performance of the manufactured engine is measured by a five-hole miniature probe, not only in design point but also in off-design operation. The results indicate that a substantial reduction in discrepancies between initial specifications, subsequent CFD simulations, and experimental investigations compared to conventional design tools relying on empirical formulations can be achieved due to the CFD-based approach. This allows the CFD-based tool to be validated for designing scalable contra-rotating fan engines. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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15 pages, 4614 KiB

Open AccessArticle

Wind Shear Response of Aircraft with C* and C*U Controller during Approach

by Yufei Yan and Lei Song

Aerospace 2024, 11(6), 476; https://doi.org/10.3390/aerospace11060476 - 17 Jun 2024

Viewed by 968

Abstract

This study investigates the impact of wind shear on the flight dynamics of commercial aircraft where C* and C*U control laws are employed during the approach phase. Given the high incidence of flight accidents during takeoff and landing attributed to wind shear, this [...] Read more.

This study investigates the impact of wind shear on the flight dynamics of commercial aircraft where C* and C*U control laws are employed during the approach phase. Given the high incidence of flight accidents during takeoff and landing attributed to wind shear, this research aims to enhance aviation safety by analyzing control law behavior under varying wind shear conditions. A nonlinear flight simulation model was developed, utilizing aerodynamic and engine data from a B737, to explore the aircraft’s response to different wind shear intensities. The simulation analysis was used to compare the response of the aircraft with C* and C*U controllers, respectively, under different wind shear, and to evaluate the effectiveness of its stability enhancement in wind shear. It was found that in most cases, the controller can achieve a good stabilization effect, but in some cases of wind fields, the aircraft suffered more significant oscillation. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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35 pages, 30394 KiB

Open AccessArticle

Stealth Aircraft Penetration Trajectory Planning in 3D Complex Dynamic Based on Radar Valley Radius and Turning Maneuver

by Xiaoqiang Lu, Jun Huang, Jingxin Guan and Lei Song

Aerospace 2024, 11(5), 402; https://doi.org/10.3390/aerospace11050402 - 16 May 2024

Viewed by 865

Abstract

Based on the quasi-six-degree-of-freedom flight dynamic equations, considering the changes in the elevation angle caused by an increase in the rolling angle during maneuvering turns, which leads to a rise in the radar cross-section. A computational model for the radar detection probability of [...] Read more.

Based on the quasi-six-degree-of-freedom flight dynamic equations, considering the changes in the elevation angle caused by an increase in the rolling angle during maneuvering turns, which leads to a rise in the radar cross-section. A computational model for the radar detection probability of aircraft in complex environments was constructed. By comprehensively considering flight parameters such as turning angle, rolling angle, Mach number, and radar power factor, this study quantitatively analyzed the influence of these factors on the radar detection probability. It revealed the variation patterns of radar detection probability under different flight conditions. The results provide theoretical support for the Radar Valley Radius and Turning Maneuver Method (RVR-TM) based on decision trees, and lay the foundation for the development of subsequent intelligent decision-making models. To further optimize the trajectory selection of aircraft in complex environments, this study combines theoretical analysis with reinforcement learning algorithms to establish an intelligent decision-making model. This model is trained using the Proximal Policy Optimization (PPO) algorithm, and through precisely defining the state space and reward functions, it accomplishes intelligent trajectory planning for stealth aircraft under radar threat scenarios. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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32 pages, 17333 KiB

Open AccessArticle

Flight Simulation of Fire-Fighting Aircraft Based on Multi-Factor Coupling Modeling of Forest Fire

by Hu Liu, Siliang Liu and Yongliang Tian

Aerospace 2024, 11(4), 267; https://doi.org/10.3390/aerospace11040267 - 29 Mar 2024

Viewed by 1133

Abstract

Forest fires can develop rapidly and may cause a wide range of hazards. Therefore, aerial firefighting, which has the ability to respond and reach fire fields quickly, is of great significance to the emergency response to and subsequent extinguishing of forest fires. The [...] Read more.

Forest fires can develop rapidly and may cause a wide range of hazards. Therefore, aerial firefighting, which has the ability to respond and reach fire fields quickly, is of great significance to the emergency response to and subsequent extinguishing of forest fires. The burning of forest fires generates a lot of heat and smoke, which changes the air flow environment and vision over the region and brings challenges to aerial firefighting. In the present work, aerial forest firefighting simulation was divided into the forest fire spread model, the air flow model and the aircraft flight dynamic and automatic control model. Each model was constructed based on a physical method. An integrated framework was designed to realize the interaction among fire fields, airfields, and aircraft, and is verified. The proposed framework can be used for the emergency response decision of aerial forest fire fighting and subsequent fire-fighting mission planning. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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24 pages, 1090 KiB

Open AccessArticle

Fuzzy Modeling Framework Using Sector Non-Linearity Techniques for Fixed-Wing Aircrafts

by Pablo Brusola, Sergio Garcia-Nieto, Jose Vicente Salcedo, Miguel Martinez and Robert H. Bishop

Aerospace 2024, 11(4), 258; https://doi.org/10.3390/aerospace11040258 - 26 Mar 2024

Cited by 1 | Viewed by 1080

Abstract

This paper presents a mathematical modeling approach utilizing a fuzzy modeling framework for fixed-wing aircraft systems with the goal of creating a highly desirable mathematical representation for model-based control design applications. The starting point is a mathematical model comprising fifteen non-linear ordinary differential [...] Read more.

This paper presents a mathematical modeling approach utilizing a fuzzy modeling framework for fixed-wing aircraft systems with the goal of creating a highly desirable mathematical representation for model-based control design applications. The starting point is a mathematical model comprising fifteen non-linear ordinary differential equations representing the dynamic and kinematic behavior applicable to a wide range of fixed-wing aircraft systems. Here, the proposed mathematical modeling framework is applied to the AIRBUS A310 model developed by ONERA. The proposed fuzzy modeling framework takes advantage of sector non-linearity red techniques to recast all the non-linear terms from the original model to a set of combined fuzzy rules. The result of this fuzzification is a more suitable mathematical description from the control system design point of view. Therefore, the combination of this fuzzy model and the wide range of control techniques available in the literature for such kind of models, like parallel and non-parallel distributed compensation control laws using linear matrix inequality optimization, enables the development of control algorithms that guarantee stability conditions for a wide range of operations points, avoiding the classical gain scheduling schemes, where the stability issues can be extremely challenging. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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24 pages, 5903 KiB

Open AccessArticle

Gliding Footprint Calculation Method for Aircraft with Thrust Failure Based on Six-Degree-of-Freedom Flight Envelope and Back-Propagation Artificial Neural Network

by Zhiwei Chen, Yuxue Ge, Jie Yuan and Yang Pei

Aerospace 2024, 11(2), 160; https://doi.org/10.3390/aerospace11020160 - 16 Feb 2024

Cited by 1 | Viewed by 1730

Abstract

In hostile environments, engine damage is of particular concern since the engine is the only component to generate thrust that affects survivability. For an aircraft suffering thrust failure, the forced landing sites should be identified within the gliding footprint, which is the reachable [...] Read more.

In hostile environments, engine damage is of particular concern since the engine is the only component to generate thrust that affects survivability. For an aircraft suffering thrust failure, the forced landing sites should be identified within the gliding footprint, which is the reachable region on the ground. This paper proposes two calculation methods to obtain the gliding footprint by finding a series of boundary points with maximum gliding distance around the aircraft. Method 1 models the thrust-failed aircraft with six-degree-of-freedom (6-DOF) flight dynamics and adopts a novel 6-DOF unpowered-flight envelope to characterize its maneuvering capabilities. Given the initial altitude when thrust failure occurs, Method 1 determines all feasible gliding distances around the aircraft based on the constructed 6-DOF flight envelope and selects the landing points of maximum gliding distances along different radial directions as the boundary points. Method 2 employs the Back-Propagation Artificial Neural Network (BP-ANN) to predict the boundary points. Using the well-trained BP-ANN, this method can estimate the maximum gliding distances with only the initial altitude and radial directions. Simulations are conducted to analyze these two methods. Compared with conventional methods using point-mass flight dynamics, Method 1 considers more flight constraints, and the gliding footprint area is reduced by 20.79%. These results are relatively conservative and can improve the safety threshold of forced landing sites. Method 2 can estimate the gliding footprints (encircled by the boundary points under the entire operational altitude and full radial direction) in real time, which reserves more response and action time for aircraft forced landing. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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24 pages, 7197 KiB

Open AccessArticle

An Energy Efficiency Optimization Method for Electric Propulsion Units during Electric Seaplanes’ Take-Off Phase

by Shuli Wang, Ziang Li and Qingxin Zhang

Aerospace 2024, 11(2), 158; https://doi.org/10.3390/aerospace11020158 - 15 Feb 2024

Viewed by 1478

Abstract

The electric seaplane, designed for take-off and landing directly on water, incorporates additional structures such as floats to meet operational requirements. Consequently, during the take-off taxiing phase, it encounters significantly higher aerodynamic and hydrodynamic resistance than other aircraft. This increases energy demand for [...] Read more.

The electric seaplane, designed for take-off and landing directly on water, incorporates additional structures such as floats to meet operational requirements. Consequently, during the take-off taxiing phase, it encounters significantly higher aerodynamic and hydrodynamic resistance than other aircraft. This increases energy demand for the electric seaplane during the take-off phase. A mathematical model for energy consumption during this stage was developed by analyzing resistance, using the propeller pitch angle as an optimization variable. This study proposes a coupled energy efficiency optimization method for the take-off phase of an electric seaplane’s electric propulsion unit (EPU). The method aims to determine an optimal propeller pitch angle configuration aligned with the seaplane’s design criteria. This ensures that the propeller output thrust meets minimal requirements during take-off while enhancing energy efficiency. Experimental validation with the two-seater electric seaplane prototype RX1E-S has demonstrated that selecting the optimal propeller pitch angle can effectively reduce energy consumption by approximately 10.4%, thereby significantly enhancing flight efficiency. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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20 pages, 6258 KiB

Open AccessArticle

A Rapid Method of Integrated Aeropropulsive Analysis for the Conceptual Design of Airbreathing Hypersonic Aircraft

by Yalin Dai, Zhouwei Fan, Jian Xu, You He and Xiongqing Yu

Aerospace 2024, 11(1), 89; https://doi.org/10.3390/aerospace11010089 - 18 Jan 2024

Cited by 1 | Viewed by 1570

Abstract

A special feature of airbreathing hypersonic aircraft is the complex coupling between aerodynamic and propulsive performances. This study presents a rapid analysis methodology for the integration of these two critical aspects in the conceptual design of airbreathing hypersonic aircraft. Parametric modeling is used [...] Read more.

A special feature of airbreathing hypersonic aircraft is the complex coupling between aerodynamic and propulsive performances. This study presents a rapid analysis methodology for the integration of these two critical aspects in the conceptual design of airbreathing hypersonic aircraft. Parametric modeling is used to generate a three-dimensional geometric model of an aircraft. The integrated aerodynamic and propulsive analysis is performed using a loosely coupled method. The aerodynamic analysis uses Euler equations to solve the inviscid aerodynamic forces, while the viscous forces are estimated using semi-empirical engineering methods. The propulsion system is modeled using hybrid one- and three-dimensional approaches. The inlet aerodynamic performance is simulated using three-dimensional simulation based on the Euler equations. The ramjet performance is estimated using a quasi-one-dimensional mathematical model. Nozzle simulation is performed using a one-dimensional plume method. The entire computational process is integrated and can be run automatically. The usefulness of the method is demonstrated through aerodynamic and propulsive performance evaluations in the conceptual design of a notional airbreathing hypersonic aircraft. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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29 pages, 17196 KiB

Open AccessArticle

Stealth Aircraft Penetration Trajectory Planning in 3D Complex Dynamic Environment Based on Sparse A* Algorithm

by Jingxin Guan, Jun Huang, Lei Song and Xiaoqiang Lu

Aerospace 2024, 11(1), 87; https://doi.org/10.3390/aerospace11010087 - 18 Jan 2024

Cited by 3 | Viewed by 1441

Abstract

To find a trajectory with low radar detection probability for stealth aircraft under the assumption of 2D space, performing a rapid turning maneuver is a useful way to reduce the radar detection probability of an aircraft by changing the azimuth angle rapidly to [...] Read more.

To find a trajectory with low radar detection probability for stealth aircraft under the assumption of 2D space, performing a rapid turning maneuver is a useful way to reduce the radar detection probability of an aircraft by changing the azimuth angle rapidly to reduce the time of high radar cross-section (RCS) exposure to radar. However, in real flight, not only does the azimuth angle to the radar change rapidly but the elevation angle also changes rapidly, and the change in the radar cross-section is also significant in this process. Based on this premise, this paper established a trajectory planning method based on the sparse A* algorithm in a 3D complex, dynamic environment, called the 3D sparse A* method, based on a log-normal radar model (the 3D-SASLRM method), which considers the RCS statistical uncertainty and the statistical characteristics of the radar signals. Simulations were performed in both simple and complex scenarios. It was concluded that the established 3D-SASLRM method can significantly reduce the radar detection probability. And the essence of reducing under the assumption of 3D space is also to reduce the time of high radar cross-section exposure to radar. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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25 pages, 12547 KiB

Open AccessArticle

An Optimized Pressure-Based Method for Thrust Vectoring Angle Estimation

by Nanxing Shi, Yunsong Gu, Tingting Wu, Yuhang Zhou, Yi Wang and Shuai Deng

Aerospace 2023, 10(12), 978; https://doi.org/10.3390/aerospace10120978 - 22 Nov 2023

Viewed by 1411

Abstract

This research developed a pressure-based thrust vectoring angle estimation method for fluidic thrust vectoring nozzles. This method can accurately estimate the real-time in-flight thrust vectoring angle using only wall pressure information on the inner surface of the nozzle. We proposed an algorithm to [...] Read more.

This research developed a pressure-based thrust vectoring angle estimation method for fluidic thrust vectoring nozzles. This method can accurately estimate the real-time in-flight thrust vectoring angle using only wall pressure information on the inner surface of the nozzle. We proposed an algorithm to calculate the thrust vectoring angle from the wall pressure inside the nozzle. Non-dominated sorting genetic algorithm II was applied to find the optimal sensor arrays and reduce the wall pressure sensor quantity. Synchronous force and wall pressure measurement experiments were carried out to verify the accuracy and real-time response of the pressure-based thrust vectoring angle estimation method. The results showed that accurate estimation of the thrust vectoring angle can be achieved with a minimum of three pressure sensors. The pressure-based thrust vectoring angle estimation method proposed in this study has a good prospect for engineering applications; it is capable of accurate real-time in-flight monitoring of the thrust vectoring angle. This method is important and indispensable for the closed-loop feedback control and aircraft attitude control of fluidic thrust vectoring control technology. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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17 pages, 1441 KiB

Open AccessArticle

A New Range Equation for Hybrid Aircraft Design

by Enrico Cestino, Davide Pisu, Vito Sapienza, Lorenzo Chesta and Valentina Martilla

Aerospace 2023, 10(11), 955; https://doi.org/10.3390/aerospace10110955 - 13 Nov 2023

Cited by 1 | Viewed by 1944

Abstract

A new Range Equation for a hybrid-electric propeller-driven aircraft was formulated by an original derivation based on the comparison of Virtual Electrical Aircraft (VEA) and Virtual Thermal Aircraft (VTA) range equations. The new formulation makes it possible to study the range of a [...] Read more.

A new Range Equation for a hybrid-electric propeller-driven aircraft was formulated by an original derivation based on the comparison of Virtual Electrical Aircraft (VEA) and Virtual Thermal Aircraft (VTA) range equations. The new formulation makes it possible to study the range of a hybrid aircraft with pre-established values of electric motor usage rate. The fuel and battery mass are defined "a priori", and do not depend on the power split, so even the aircraft’s total mass is constant. The comparison with the typical range formulas available for hybrid aircraft was made on the basis of a reference composite VLA category aircraft manufactured by the CFM Air company. The analysis carried out shows that there is an optimum hybridization level as a function of the pre-set specific energy of the batteries system. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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22 pages, 7219 KiB

Open AccessArticle

Multiscale Aeroelastic Optimization Method for Wing Structure and Material

by Keyu Li, Chao Yang, Xiaozhe Wang, Zhiqiang Wan and Chang Li

Aerospace 2023, 10(10), 866; https://doi.org/10.3390/aerospace10100866 - 2 Oct 2023

Viewed by 1523

Abstract

Microstructured materials, characterized by their lower weight and multifunctionality, have great application prospects in the aerospace field. Optimization methods play a pivotal role in enhancing the design efficiency of both macrostructural and microstructural topology (MMT) for aircraft. This paper proposes a multiscale aeroelastic [...] Read more.

Microstructured materials, characterized by their lower weight and multifunctionality, have great application prospects in the aerospace field. Optimization methods play a pivotal role in enhancing the design efficiency of both macrostructural and microstructural topology (MMT) for aircraft. This paper proposes a multiscale aeroelastic optimization method for wing structure and material considering realistic aerodynamic loads for large aspect ratio wings with significant aeroelastic effects. The aerodynamic forces are calculated by potential flow theory and the aeroelastic equilibrium equations are solved through finite element method. The parallel design of the wing MMT is achieved by utilizing the optimization criterion (OC) method based on sensitivity information. The optimization results indicate that wing elastic effects reinforce the outer section of the wing structure compared with the optimization results obtained under rigid aerodynamic forces. As the optimization constraints become more rigorous, the optimization results show that the components with larger loads are strengthened. Furthermore, the method presented in this paper can effectively optimize the wing structure under complex boundary conditions to achieve a reasonable stiffness distribution in the wing. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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17 pages, 3232 KiB

Open AccessArticle

Research on Fault-Tolerant Control of Combined Airframe Damage of Electric Aircraft

by Lei Zhang, Jin Mu, Hongtu Ma, Guicheng Dai and Shengxi Tong

Aerospace 2023, 10(7), 611; https://doi.org/10.3390/aerospace10070611 - 2 Jul 2023

Cited by 3 | Viewed by 1294

Abstract

General aviation is an important branch of the aviation field. As a green energy aircraft, the electric aircraft is an important component and development direction of general aviation aircraft, and its safety is crucial. In this paper, the aerodynamic and dynamic characteristics of [...] Read more.

General aviation is an important branch of the aviation field. As a green energy aircraft, the electric aircraft is an important component and development direction of general aviation aircraft, and its safety is crucial. In this paper, the aerodynamic and dynamic characteristics of electric aircraft under collision, lightning strikes, and icing conditions are studied, and the dynamic and kinematics models of the aircraft are established by introducing damage factors. The STAR-CCM+ software is used to simulate the aerodynamic force and aerodynamic moment in the case of combined airframe damage. Based on the estimation ability of the L1 adaptive control algorithm for the parameter uncertainty of the controlled object and the automatic adjustment ability of control output, a fault-tolerant control law for electric aircraft is designed in the case of wing damage, horizontal tail damage after a collision, horizontal tail icing, and wing lightning damage. The results show that the control law has good fault-tolerant control ability for combined airframe damage of electric aircraft, and the control system has adaptability, anti-interference, and robustness, which has a good engineering reference significance for flight safety control of other transport aircraft. Full article

(This article belongs to the Special Issue Advanced Aircraft Technology)

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