Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

Round 1

Reviewer 1 Report

the english language must be substantially improved (e.g. revise the sentences highlighted in yellow in the attached revision paper). also the quality of presentation is not satisfactory (e.g. answer to the question in the attached revision paper). in the introduction, better explain the aims of your work. check that all the variables introduced in the formulas are defined.

 

 

Comments for author File: Comments.pdf

Author Response

Dear professor and dear reviewers

Re: Manuscript ID: aerospace-1989301 and Title: Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

Thank you for your letter and the reviewers’ comments concerning our manuscript. Those comments are valuable and very helpful. We have read through comments carefully and have made corrections. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions in the text are shown using red highlight for additions, and strike through font for deletions. The responses to the reviewer's comments are marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

Best regards.

Qi Yuanjie.

 

Point 1: with FEM you can get numerical data not experimental data

Response 1: ‘experimental’ data has changed into ‘simulation data’.

 

Point 2: why do you say "obviously conservative"? non linear models sometimes turn out to be non conservative.

Response 2: Because the thinning of inner wall is ignored in thrust chamber.

 

Point 3: what is thickness alternation?

Response 3: Thickness variation.

 

Point 4: not clear for 40 lifetimes

Response 4: Maximum instability life is about 38 lifetimes.

 

Point 4: alternation?

Response 4: Has changed into variation.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is good as it it. It can be accepted without any changes

Author Response

Dear professor and dear reviewers

Re: Manuscript ID: aerospace-1989301 and Title: Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

Thank you for your letter and the reviewers’ comments concerning our manuscript. Those comments are valuable and very helpful. We have read through comments carefully.

Best regards.

Qi Yuanjie.

Author Response File: Author Response.docx

Reviewer 3 Report

MDPI Aerospace

Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

 

1. Page 2; line 72;

It is advised to add more details of plastic ratchet effect.

 

2 Page 3; line 95-99

What it the meaning of ‘life factor analysis’? The statement of ‘life factor analysis’ is somehow ambiguous. In addition, the purpose of this work should be stated more clearly, in line with contributions.

 

3. Please add nomenclature for all symbols. Although some of them are stated in the manuscript, yet some of them are missing.

 

4. Page 6; line 161-162;

The description for Figure 3 is missing in the manuscript. All figures should be described in the manuscript.

 

5. Page 6; line 163-164;

The statement for life prediction should be described more in detail. Only two sentences are too short.

 

6. Page 7; figure 5

Please add the location information of chamber, throat, nozzle along with x-axis.

 

7. Page 8; table 3

‘Tables may have a footer.’ may be deleted.

8. Page 8; line 211-213;

The ‘life of instability’ did not appear in figure 6. And the statement for figure 7 is missing.

 

9. ‘life of instability’ vs. ‘life of plastic instability’

Do these two words denote different phenomena? If they were same, authors should use one word throughout the manuscript.

 

10. Page 10; figure 9

The results of life of plastic instability are almost(?) identical between (P) and (C) model, and the detail description for reason is missing in the manuscript.

 

11. Section 4.4

The more details should be added for the results of Figures 12, 13 and 14.

 

12. Page 12; line 277-279

Please add the mathematical definition of Rib Filling Ratio.

 

13. Section 5

Some conclusions are somehow obvious.

It is recommended that authors should enrich their findings and suggestions.

 

Author Response

Dear professor and dear reviewers

Re: Manuscript ID: aerospace-1989301 and Title: Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

Thank you for your letter and the reviewers’ comments concerning our manuscript. Those comments are valuable and very helpful. We have read through comments carefully and have made corrections. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions in the text are shown using red highlight for additions, and strike through font for deletions. The responses to the reviewer's comments are marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

Best regards.

Qi Yuanjie.

 

Point 1: Page 2; line 72;

It is advised to add more details of plastic ratchet effect.

Response 1: According to the references, the dog-house failure of the thrust chamber is caused by plastic ratchet effect.

 

Point 2: Page 3; line 95-99

What it the meaning of ‘life factor analysis’? The statement of ‘life factor analysis’ is somehow ambiguous. In addition, the purpose of this work should be stated more clearly, in line with contributions.

Response 2: The aim of this work is analysis the parameters affect the life of thrust chamber which contains pressure and temperature difference and structural parameters. Perhaps ‘life analysis’ is better?

 

Point 3: Please add nomenclature for all symbols. Although some of them are stated in the manuscript, yet some of them are missing.

Response 3: 

 

Point 4: Page 6; line 161-162;

The description for Figure 3 is missing in the manuscript. All figures should be described in the manuscript.

Response 4: The description for Figure 3 has added in the manuscript.

 

Point 5: Page 6; line 163-164;

The statement for life prediction should be described more in detail. Only two sentences are too short.

Response 5: Some experiment data of thrust chamber materials is quite hard to acquire, only OFHC copper and Narloy-Z alloy is available in the references.

 

Point 6: Page 7; figure 5

Please add the location information of chamber, throat, nozzle along with x-axis.

Response 6: Nozzle information has been added.

 

Point 7: Page 8; table 3

‘Tables may have a footer.’ may be deleted.

Response 7: ‘Tables may have a footer.’has been deleted.

 

 

Point 8: Page 8; line 211-213;

The ‘life of instability’ did not appear in figure 6. And the statement for figure 7 is missing.

Response 9: The ‘life of instability’ is provided in figure 7.

 

Point 9: ‘life of instability’ vs. ‘life of plastic instability’

Do these two words denote different phenomena? If they were same, authors should use one word throughout the manuscript.

Response 9: They were the same phenomena, ‘life of plastic instability’ has been changed into ‘life of instability’ .

 

 

Point 10: Page 10; figure 9

The results of life of plastic instability are almost(?) identical between (P) and (C) model, and the detail description for reason is missing in the manuscript.

Response 10: Figure 9 is approximate the same, because of delta3 is quite small in the calculation. The detail description for reason is added in the manuscript.

 

 

Point 11: Section 4.4

The more details should be added for the results of Figures 12, 13 and 14.

Response 11: Details has been added.

 

Point 12: Page 12; line 277-279

Please add the mathematical definition of Rib Filling Ratio.

Response 12: Mathematical definition of Rib Filling Ratio has been added in formula(22).

 

Point 13: Section 5

Some conclusions are somehow obvious.

It is recommended that authors should enrich their findings and suggestions.

Response 13: Suggestions has been enriched.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

some typos are still present (please check in the attached file the parts highlighted in yellow and red). 

you can enrich bibliography considering the following paper whose aim is to implement an iterative coupling technique between two finite element models, a Global linear model and a Local nonlinear one, in the framework of a Global/Local procedure, to improve the accuracy of the numerical simulations for liquid rocket engines.

1)       Ferraiuolo, M.; Leo, M.; Citarella, R. On the Adoption of Global/Local Approaches for the Thermomechanical Analysis and Design of Liquid Rocket Engines. Appl. Sci. 2020, 10, 7664.

Comments for author File: Comments.pdf

Author Response

Dear professor and dear reviewers

Re: Manuscript ID: aerospace-1989301 and Title: Life Analysis of Reusable Liquid Rocket Engine Thrust Chamber

Thank you for your letter and the reviewers’ comments concerning our manuscript. Those comments are valuable and very helpful. We have read through comments carefully and have made corrections. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions in the text are shown using red highlight for additions, and strike through font for deletions. The responses to the reviewer's comments are marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

Best regards.

Qi Yuanjie.

Author Response File: Author Response.pdf