Simulation of Mass and Heat Transfer in an Evaporatively Cooled PEM Fuel Cell

Round 1

Reviewer 1 Report

The manuscript presents a 3D model of the evaporative cooling process in fuel cells based on a study conducted by Cochet et al. The model is described in details with figures and illustrations to assist the reader to understand it. The results presented are interesting and therefore I would recommend this paper for publications. The authors however should consider the following minor changes in order to improve the quality of the presentation and ease of following the results in the text.

1. Many abbreviations are used in the text which made the text difficult to follow, especially when needing to go back to the definitions to understand the points made.
2. The result figures 4, 5 and 6 are complicated to follow, there is a lot of results in the figures and they are impressive to look at but you can easily get lost in the figure which makes understanding the results difficult. I suggest to simplify/ break the each into multiple figures focusing on one dimension (domain boundary) of the analysis. This will also assist in citing and explaining the result in the text. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In this work, the authors explained the simulation of mass and heat transport processes in an evaporatively cooled proton exchange membrane fuel cell. This article addressed the COMSOL Multiphysics version 5.6 software explanation, transport mechanism (water and heat), comparison (experiment and theoretical model), and result & discussion. The present work has a lack of novelty and there are no applications. Based on the journal's merit, the present manuscript cannot be considered for publication in “Energies”.

1. There are a lot of grammatical and typo errors in this manuscript. Therefore the author should review and revise the manuscript in detail.
2. The title is not concise.
3. In the introduction part, Cochet et al analytical model explanations are very short.
4. In section 2.6 the boundary and initial conditions explanation are not sufficient.
5. The comparison table is necessary to compare the properties of present theoretical results with other recently reported literature.
6. The manuscript has no detailed explanations despite the existence of references.
7. In this manuscript, many improper references were added some of not addressed [note- we should keep journal reputation and format].

Author Response

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Reviewer 3 Report

In this paper, the authors developed a 3D model to simulate the concept of evaporative cooling in the fuel cell. The research content and the literature review is sufficiently good, so I suggest a minor revision. The main points I am concerned about are as follows for reference in the revision.

1. Line 128: why is the flow laminar? How to determine it has fully developed.
2. How many boundaries did you have in the model? I suggest you also note the boundaries and interfaces in the figure and/or summarize them in a Table. It is not easy to recognize all the details in the manuscript.
3. Figure A2, what is the definition of △x _t-p? I could not find it in the symbol list.
4. Line 363, the element size is less than 0.01μ. What is the increment of grids from the interface to the chamber body? Have you tested the effects of local grids on the modeling results?
5. What is the total grid number of your model?
6. In Line 388, the modeling results are compared to both the experiments and the analytical model, but only the analytical model is shown in Figure 3.

Author Response

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