Robust Optimization of Natural Laminar Flow Airfoil Based on Random Surface Contamination
Round 1
Reviewer 1 Report (New Reviewer)
Reviewer’s Comments on applsci-1885420
Robust optimization of natural laminar flow airfoil based on 2 random surface contamination
This paper presents a method based on the NSGA-II and Monte Carlo Analysis for the robust optimization of natural laminar flow under surface contamination. The authors present a comparison of the proposed robust method and the normal optimization method. All in all, I consider that this is an interesting manuscript with interesting contributions. I have the following comments:
1. The authors are encouraged to present a more up-to-date literature review as most of the references have more than 5 years of being published. Only 4 of the 26 references are from 2018 to 2020. This presents a serious concern.
2. The authors are encouraged to perform a thorough review of the manuscript as there are several grammar and syntax issues. For example. Line 41 “long time use”, line 52 does not make sense in the sequence of ideas, line 92 “comes. Figure…
, etc…
3. From line 34 to line 36 and line 78 to 82, the authors discuss works from different authors, but do not present the citations accordingly, only the names. Please present the citations correctly.
4. Please highlight convincingly the main contributions of the manuscript. The authors present a general review of related works at the end of the introduction. But a deep discussion of the disadvantages of these approaches is missing. Furthermore, there are several published work that deal with optimization methods considering uncertainty quantification or robust approaches for natural laminar flow, please discuss more works.
5. Please include appropriate citations for the statement of the critical value in line 103-104.
6. Please cite in the parametrization method to:
-WANG, Yueqing, et al. An Intelligent Method for Predicting the Pressure Coefficient Curve of Airfoil-Based Conditional Generative Adversarial Networks. IEEE Transactions on Neural Networks and Learning Systems, 2021.
7. Although the conclusions are presented as a summary. Insights for further research are not discussed. Based on the obtained results, please include aspects of the proposed approach that can be extended.
Minor revisions:
- Give the meaning of UAV in line 40.
- Please make the reference format uniform.
Author Response
Thanks for your suggestions to my paper which is definitely crucial for the improvement of its academic value. It is clear that you have much experience and excellent insight into aerodynamic optimization problems and paper writing. Your suggestions will be of great help in my following research. I have compiled the responses to your suggestions in table 1 with big changed expressions marked in red in the paper. Finally, thank you again for your valuable suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report (New Reviewer)
applsci-1885420-peer-review-v1
Robust optimization of natural laminar flow airfoil based on random surface contamination.
The paper is written well. Even though, there are many serious technical issues. Authors should clarify the following comments:
1. Uncommon abbreviations should be spelled out at first use. Line 27, for instance, NASA.
2. Add a transition paragraph and describe every section as the last paragraph of introduction.
3. I have not seen any major finding in the work related to the several literatures exist. Authors have completely missed the clear objective and major highlights in the introduction section to strength the new finding in the work.
4. The introduction section is too long. Please separate the literature review section.
5. The structure of the introduction section is not good. It should have two separate paragraphs at its end, one of which presents the contribution and explanations of this work; and the other one outlines the coming sections.
6. Please point out the comparison criteria for evaluating the performance
of applied method.
7. There are numerous novelty claims in this manuscript which I found unnecessary. This is eventually for the editor to decide, but I feel some of them are clearly overstated. For example, line 297, the authors mentioned " Finally, it can be seen that the robust optimization method can effectively improve the robust of the natural laminar flow ". But I suspect this is mainly because it is not the best approach.
8. Few studies have been reviewed. However, only the strong parts of the reviewed studies have been emphasized which makes the contribution of the proposed paper unconvincing. The disadvantages of reviewed studies should be highlighted. The new features of the proposed method and the main advantages of the results over others should be clearly described. The author(s) must highlight in 4-6 lines what gaps are observed in existing literature, which has led to the design of the proposed method in this paper.
9. The last section (i.e., Section 5), should be just “Conclusions”.
10. Make a separate section, namely “Result and Discussions”. Authors missed the analysis and interpretation of the research result. Authors have to explain the discussion so the readers will be understanding easily your research contribution and finding.
11. Many references are not in proper format. For instance, see References 2-5.
12. In the conclusion section, please revise it and improve it by re-organizing it into one paragraph only including the suggested future work. The current conclusion does not highlight the value of the article, and it overlaps with the content in the abstract and introduction.
13. Even though the authors proofread the manuscript, there are still too many grammatical issues in the article. Many expressions and languages used are inappropriate.
***
Author Response
Thanks for your suggestions to my paper which is definitely crucial for the improvement of its academic value. It is clear that you have much experience and excellent insight into aerodynamic optimization problems and paper writing. Your suggestions will be of great help in my following research. I have compiled the responses to your suggestions in table 1 with big changed expressions marked in red in the paper. Finally, thank you again for your valuable suggestions.
Author Response File: Author Response.docx
Reviewer 3 Report (New Reviewer)
The topic is interesting but the academic writing style is poor.
No introduction section, no contribution list, no describition of the paper sturdture
. The orginzation of the paper is poor as well which make it hard to read and understand
The Authors should rewite the entire manuscript considering
-the abstract should rewrite entirely. It should briefly state a two lines of introduction of topic then two lines of the research problem .Then the proposed solution and methodology and finally the results and implications.
- add NSGA-II within the keyword list
- add introduction section including at the end a list of contributions and the paper structure.
- make a separate section for expermatinal setting and another section for the experiments.
- in conclusion section, state the particular implications for you work.
The author needs to justify the decisions that made in the article.
English level must be improved.
Author Response
Thanks for your suggestions to my paper which is definitely crucial for the improvement of its academic value. It is clear that you have much experience and excellent insight into aerodynamic optimization problems and paper writing. Your suggestions will be of great help in my following research. I have compiled the responses to your suggestions in table 1 with big changed expressions marked in red in the paper. Finally, thank you again for your valuable suggestions.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report (New Reviewer)
The authors considered the provided comments to improve the manuscript. However, there are still some minor issues that need to need to be corrected.
-The authors are encouraged to perform a second thorough review of the manuscript to correct grammar and syntax issues, for example, in the first line of the paragraph, should be a space "laminar-flow (NLF)", the same in line 50 "vehicle (UAV)" and line 106, in line 119 should be "airfoil are less than", line 144 should be "same", line 212 should be "an obviously". Line 235 should be "Figure 15. The". As these examples, there are several issues that need to be carefully corrected.
-In the fourth previous comment the authors were asked to present a deep discussion of the disadvantages of the previous published approaches to enhance the proposed method. The authors included some citations, but the deep discussion is still missing.
Author Response
Dear Professor
Thank you for your comments on my essay. I have revised my essay according to the minor revisions suggestions and uploaded the revised version. Your valuable suggestions have played a key role in improving the quality of my essay. Once again, I would like to express my gratitude.
Author Response File: 
Author Response.pdf
Reviewer 2 Report (New Reviewer)
No comment
Author Response
Dear Professor
Thank you for your comments on my essay. I have revised my essay according to the minor revisions suggestions and uploaded the revised version. Your valuable suggestions have played a key role in improving the quality of my essay. Once again, I would like to express my gratitude.
Reviewer 3 Report (New Reviewer)
The authors did all comments. The manuscript is accepted in the current form.
Author Response
Dear Professor
Thank you for your comments on my essay. I have revised my essay according to the minor revisions suggestions and uploaded the revised version. Your valuable suggestions have played a key role in improving the quality of my essay. Once again, I would like to express my gratitude.
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments for author File: Comments.pdf
Author Response
Dear Professor
Thanks for your suggestions to my paper which is definitely crucial for the improvement of its academic value. It is clear that you have much experience and excellent insight into multi-objective optimization problems and your suggestions will be of great help in my evolutionary algorithm research. I also believe that these improvements will help me to obtain better optimization results in my following scientific research. I have compiled the responses to your suggestions in table 1 with changed expression marked in red in the paper. Finally, thank you again for your valuable suggestions.
Table 1
|
|
Advice |
Response |
|
0 |
This sentence is incomplete: “In order to further visualize the effect of surface contamination effects perform the related aerodynamic analysis.” |
Perform the related aerodynamic analysis to get further understanding about the effect of surface contamination effects |
|
1 |
The first time “CST” appears, we should write out the acronym as “Class/Shape Transformation”. |
“Class/Shape Transformation(CST)” |
|
2 |
There is too much spacing between the quantity and reference 14: “2.0 *10^6 [14]”. |
Delete the spacing |
|
3 |
Fig. 3, 4, 9, 11, 12, 13, 16 and 19 are too small. It is very difficult to read them correctly. |
Enlarge those images |
|
4 |
The main author of the NSGA and NSGA-II algorithms is Kalyanmoy Deb not “Ded”. |
“Kalyanmoy Deb” |
|
5 |
Did the authors experiment with different population size? |
The optimization parameters were set using experience from former practice. In addition, I set the number of populations to 24 and 36, assuming a triangular probability distribution, the overall results were better but not to a great extent. Pop. Size 24 36 Mean 0.0084 0.0082 Stan. dev. 0.0010 0.0010 |
|
6 |
How many runs? |
Only one run was carried out in the previous period. Now we have made up three optimizations with a population size of 12 assuming a triangular probability distribution and found that the actual result has fluctuations but the fluctuations are small. Pop. Size 12 12 12 Mean 0.0084 0.0085 0.0082 Stan. dev. 0.0010 0.0009 0.0010 |
|
7 |
What is the normal optimization procedure? Which algorithm? |
The procedure of normal optimization is the same as robust optimization but it doesn’t have monte carlo analysis. Normal optimization also use NSGA-II algorithm. |
|
8 |
Please explain the difference between the population size and the number of non-dominated solutions. |
The difference is caused by the constraints. Some points couldn’t satisfy the constraints so I take them away. Apparently, the former distribution has less failed points so the Fig.14 seems to have more points. |
|
9 |
The paper suggests the “green point” as solution (Fig. 14 and 17). Why? What to do if we have an M-objective problem with M > 3? |
Actually I choose their sum to be the smallest, which is to give them equal weight factor. If we have an M-objective problem with M > 3, we also could choose proper weight factor according to the problem. |
|
10 |
This sentence is incomplete: “… using the idea of uniform distribution which similar to the Latin hypercube…”. |
“While descriptive sampling method divides the random variables in space according to setting probability, then distribute points in divided space according to uniform distribution” |
|
11 |
What is “uncertainty variety of the problem”? |
It is“uncertainty variable of the problem” |
|
12 |
Is there a reason for the case where triangular distribution is used? |
Firstly, considering the linear superposition of perturbation which caused by uniform surface contamination effects. Secondly, make conclusions more general by adopting a different probability distribution. |
|
13 |
Following Fig. 13, there are equation variables that not aligned with the text. They appeared as raised text within a paragraph. |
Changed |
Author Response File: Author Response.pdf
Reviewer 2 Report
The paper presents a robust optimization of an airfoil by combining NSGA-II amd MCS where the modeling is performed by means of XFoil. The overall quality of the paper is low (language, quality of figures, reference list, description of methods, ...) and is not innovative and can thus not be considered for publication. First, no clear research question/gap is defined that is treated in the work. Second, the use of XFoil within an aerodynamic research context is hard to defend since more accurate (CFD) models are available with affordable computational expense. Third, no innovation is presented in regards to the robust optimization scheme. Fourth, the results obtained are trivial.
Author Response
Dear professor,
I feel very sorry that you think this paper is not of great academic value. After lots of researches there are very few airfoil optimization studies that consider the use as well as maintenance of wings, but during the use of laminar flow wing, it is a very demanding problem. For example, the cleaning of surface stains on high performance gliders’ wings requires the use of special equipment and takes a long time to ensure that the surface of wing is not scratched. Therefore, this is undoubtedly of great importance both in practicality and economy if surface contamination can be taken into account at the beginning of the airfoil design. Also, I have noticed your suggestions about the language as well as format and already made improvements. Finally, I would like to thank you for your valuable comments.
Round 2
Reviewer 2 Report
Careful inspection of the second version indicated that barely any chances were made to the document. The increase of paper length was caused by the enlargement of the figures. This is unacceptable. Second, the response of the authors does not answer my previous remarks regarding 1. research question, 2. modeling, 3. innovation and 4. results. Furthermore, the body of literature regarding aerodynamic optimization under uncertainty is enormous, as such I consider the response of the authors to be incorrect. I therefore must object to the publication of this work.
