Thermodynamic Performance Comparisons of Ideal Brayton Cycles Integrated with High Temperature Fuel Cells as Power Sources on Aircraft

Round 1

Reviewer 1 Report

 

- Lack of validation or verification.

- There are many assumptions without the proper references.

- There is a huge mathematical modeling which does not suit to a paper but maybe it is better for a bookc chapter. Also, very basic equatiosn are given.

Author Response

Dear Reviewers and Editor,

We are grateful to the reviews and editor for their helpful comments according to which we have made modifications in the following aspects. The point-to-point answers and explanations for all comments, and the followings are the reviewers’ comments (in black) and my replies (in red). We hope, with these modifications and improvements based on your suggestion and the reviewers' comments, our manuscript would be considered for the publication on the Sustainability. Once again, we acknowledge your comments and constructive suggestions very much, which are valuable in improving the quality of our manuscript. If you have any questions about this paper, please contact us without hesitation. Email: [email protected]

 

Best regards,

Tingting Zhu

Author Response File: Author Response.docx

Reviewer 2 Report

- Citation in text should be edited.

- Conclusion: Too long, its must be concise 

- Bibliography needs to be further improve, particularly journal name and format should be consistent

Author Response

Dear Editor and Reviewers,

We are grateful to the reviews and editor for their helpful comments according to which we have made modifications in the following aspects. The point-to-point answers and explanations for all comments, and the followings are the reviewers’ comments (in black) and my replies (in red). We hope, with these modifications and improvements based on your suggestion and the reviewers' comments, our manuscript would be considered for the publication on the Sustainability. Once again, we acknowledge your comments and constructive suggestions very much, which are valuable in improving the quality of our manuscript. If you have any questions about this paper, please contact us without hesitation. Email: [email protected]

 

Best regards,

Tingting Zhu

 

Author Response File: Author Response.docx

Reviewer 3 Report

Title: Thermodynamic performance comparisons of ideal Brayton cycles integrated with high temperature fuel cells as power sources on aircraft.

Authors: Zhixing Jiab; Fafu Guoa; Tingting Zhucd*; Kunlin Chengb; Silong Zhangb; Jiang Qinb; Peng Dongb

1.       Inlcude more quantitative results in the Abstract.

2.       Avoid lumping references

3.       Many expressions are not suitable for academic article such as “a lot of”.

4.       What do you mean by “Currently, almost no relevant research papers on this topic have been published”.

5.       Please justify your bold claim on your novelty by presenting previous studies in a table and indicating your gap.

6.       Please elaborate more on this statement. The reason is that the SOFC active area will be extremely huge if the performance of the SOFC is achieved under ideal conditions.

7.       Remove any general equations and focus more on your findings.

8.       Relate the findings with other studies whenever possible.

 

Author Response

Dear reviewers and editor,

We are grateful to the reviews and editor for their helpful comments according to which we have made modifications in the following aspects. The point-to-point answers and explanations for all comments, and the followings are the reviewers’ comments (in black) and my replies (in red). We hope, with these modifications and improvements based on your suggestion and the reviewers' comments, our manuscript would be considered for the publication on the Sustainability. Once again, we acknowledge your comments and constructive suggestions very much, which are valuable in improving the quality of our manuscript. If you have any questions about this paper, please contact us without hesitation. Email: [email protected]

 

Best regards,

Tingting Zhu

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

- Please add some senetnses where you state about the validation from the other work. Say teh mean deviations, etc.

- Enhance the discussion of your work by comapring your results with others from the literature.

Author Response

Journal Name: Sustainability
Manuscript Title: Thermodynamic performance comparisons of ideal Brayton cycles integrated with high temperature fuel cells as power sources on aircraft (Sustainability-2054754)

 

Dear Editor,

We are grateful to the reviews and editor for their helpful comments according to which we have made modifications in the following aspects. The point-to-point answers and explanations for all comments, and the followings are the reviewers’ comments (in black) and my replies (in blue). We hope, with these modifications and improvements based on your suggestion and the reviewers' comments, our manuscript would be considered for the publication on the Sustainability. Once again, we acknowledge your comments and constructive suggestions very much, which are valuable in improving the quality of our manuscript. If you have any questions about this paper, please contact us without hesitation. Email: [email protected]

 

Comments by Reviewers:

1. Please add some senetnses where you state about the validation from the other work. Say teh mean deviations, etc

Answer: Thank you for your valuable suggestions. We have added the mathematical description in the Supplementary material 1.

Model verification and validation (V&V) assessments

Verification assessment

The purpose of verification is to quantify the error of a numerical simulation by demonstration of convergence for the particular model under consideration. [1] The key component in the hybrid engine is an SOFC. The rest of component models have been widely cited and are without verification assessments. Based on modeling and governing equation discussed, the calculation results obtained from thermodynamic analysis of SOFC have been validated with calculation results of Aguiar [2] et al. and the results have been found to be in good agreement with works as shown in Fig. 1. The standard deviation is less than 1%. The code-to-code comparisons as a means of calculation verification is completed, which provide circumstantial evidence.

Fig. 1 Verification of the SOFC model

Fig. 2 Validation assessment of the SOFC model

Validation assessment

The validation assessment is the process of determining the degree to which a model is an accurate representation of the real world from the perspective of the intended uses of the model. [3] The goal of validation is to quantify confidence in the predictive capability of the model by comparison with experimental data. [1] The SOFC simulation results is compared with the experiment work of Suwanwarangkul [4] et al. The results have been found to be in good agreement with experiment works as shown in Fig. 2. The standard deviation is less than 3%. In general, the models built in this paper may exactly describe the thermodynamic processes in the real word.

References

[1] B.H. Thacker, S.W. Doebling, F.M. Hemez, M.C. Anderson, J.E. Pepin, E.A. Rodriguez. Concepts of model verification and validation. Los Alamos National Lab.2004.

[2] P. Aguiar, C.S. Adjiman, N.P. Brandon. Anode-supported intermediate temperature direct internal reforming solid oxide fuel cell. I: model-based steady-state performance. Journal of Power Sources. 138 (2004) 120-36.

[3] A.I.o. Aeronautics, Astronautics. AIAA guide for the verification and validation of computational fluid dynamics simulations. American Institute of aeronautics and astronautics1998.

[4] R. Suwanwarangkul, E. Croiset, E. Entchev, S. Charojrochkul, M. Pritzker, M. Fowler, et al. Experimental and modeling study of solid oxide fuel cell operating with syngas fuel. 161 (2006) 308-22.

 

2. Enhance the discussion of your work by comparing your results with others from the literature.

Answer: Thank you for your valuable suggestions. We have added the contents in Section 4.1. The highest-pressure ratio will be 32.4 because the designed maximum SOFC temperature difference  of 200K will be reached. The conclusions are consistent with that in the Ref^[31], which revealed that the simplified analysis method is useful to demonstrate the effect of the fundamental parameters on the system. //Thermodynamic performance evaluation of a turbine-less jet engine integrated with solid oxide fuel cells for unmanned aerial vehicles[J]. Applied Thermal Engineering. 2019; 160:114093.

 

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

DONE!