Study on the Influence of a Powered Nacelle on the Wake Vortex Characteristics of Wide-Body Aircraft
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsAccording to the authors' statement, the paper is devoted to studying the effect of «Powered Nacelle» on the vortex wake of «Wide-Body».
The paper should certainly be rejected for the following reasons:
1. Despite the presence of 8 people in the author's team, none of them read the whole article. Otherwise, it is impossible to explain the large number of syntax errors in the text, the lack of figures and typos.
2. It is hoped that the Introduction is written with the help of ChatGPT or other generative AI. Otherwise, we can only assume some degree of disrespect of the authors towards the editors, readers and reviewers.
3. The Abstract is obviously also written using AI-assisted technology or carelessly translated into English, as evidenced by the incorrect use of terms.
4. Despite the statement that the LES method is used in the study, it is not described in any way, neither is its use in conjunction with RANS. The RANS method is described in one sentence.
5. Section 2.2. is not relevant to the paper because it describes other computational cases and a different approach to numerical simulation. If a research group wants to prove that it can do CFD, they should do it in another way.
6. The title of section 3.2 does not correspond to the content, since here, obviously, data for a zero thrust are given.
7. Although the simplified approach in jet modeling seems to be justified, the numerical simulation methodology is not described, which raises doubts about the correctness of the main results of the paper.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors combined RANS and LES to numerically study the wake structures of airplane jets. Both verification and validation studies were performed, which make the work overall solid. The manuscript is also well written, but proofread is needed to correct mistakes here and there, e.g., line 248.
The reviewer also has the the following two questions:
1. In Figures 7 and 8, are these results the instantaneous flow fields or (phase) averaged ones? If they are the former, where are the small/fine turbulent vortices? Since LES is used, one would expect much better resolved vortices in the wake region. The present results still look very RANS.
2. Since you already have full-field RANS result and half-field LES result, why not do a comparison between the two to show the differences, advantages, etc., of the methodology used?
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsManuscript Number: aerospace-2979018-v1
Full Title: Study on the Influence of Powered Nacelle on the Wake Vortex Characteristics of Wide-Body
I – General Comments
The present paper numerically investigates the wake of a large aircraft as a leading aircraft including the engine jet interference on the wake. In my opinion, the manuscript needs some improvement before my acceptation to be published as an Aerospace’s paper.
II - Specific Comments
(i) Extensive editing of English language required.
(ii) In “Abstract”: It is necessary to reorganize it. In general, the “Abstract” should describe the objectives, context, and significance of the research, methods, results, and main conclusions of the paper in about 200 words. The authors also need to justify the intended publication in Aerospace.
(iii) Keywords from authors: “wake vortex; powered nacelle; jet stream; ring volume; numerical simulation.” The group of keywords reflects the manuscript scope.
(iv) The authors used appropriate, but mostly older specialized literature in the elaboration of the manuscript. More than 56% of the literature used is older than 15 years. Only 16% of the professional literary sources used have been published in the last four years. Thus, the manuscript needs some citations to contextualize the art state for the investigated topic.
(v) On page 4, line 160, the authors have properly commented the following: “There is still a lack of interference between aircraft components and the wake flow, especially the interaction between the engine jet and the wake flow, and the interference process and mechanism are still unclear. Therefore, this paper will conduct a numerical simulation study on the wake of a large aircraft as a front aircraft and compare and analyze the influence of the engine jet on the wake.”
Closing the “Introduction” of the present manuscript, the authors must show why the work is important and how it will contribute to the research field. In closing, Section 1 must detail about the adopted numerical approach including a short description of the advantages in comparison with other techniques already tested in the literature.
(vi) The Section 2 is poor in terms of Mathematical Formulation. There is no discussion/inclusion concerning the assumed hypotheses, governing equations and boundary conditions. The authors must include important information about mathematical formulation; a figure illustrating the problem geometry is welcome too.
(vii) A Table summarizing the symbols and notation in the text must be provided too.
(viii) Figure 2 needs to be better introduced and interpreted.
(ix) In my copy, there is an empty space between lines 251 and 252. I understood that Figure 3 vanished. What happened?
(x) What is the Reynolds number sensitivity for Mach number under subsonic flow condition?
(xi) Section 3.2 has discussed effect of powered nacelles on aircraft wake vortex. The results are interesting. However, it is recommended more physics sense when discussing numerical results behaviors.
(xii) Figures 11-13 illustrates the far field wake vortex patterns at different jet intensities at cruising angles of attack. Please, provide some legend to identify those intensities.
(xiii) In “Conclusion”: It is necessary to include comments with respect the numerical results behaviour as compared as previous works (specially, experimental data of reference). The readers need to be better convinced of the novelties from present work. In closing, it is important to complete “Conclusion” with perspectives for a future research. What are the drawbacks of the present numerical approach? And what are the ways to resolve them? More details should be provided. Finally, the main contribution of the present manuscript should be clarified aiming to justify its publication in Aerospace.
III - Recommendation for the Aerospace´ editor
In my opinion, the present manuscript needs attend all topic above presented. Upon consideration of all points above, plus a thorough revision for typos and notation errors, I think that the work could be considered for publication. Originality/novelty is good. Clarity and writing need of a rigorous improvement to attend the Aerospace’s standard.
Comments on the Quality of English LanguageExtensive editing of English language required.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors
A wake vortex behind an aircraft can have a significant impact (usually negative) on on aircraft flying near this vortex. Despite the fact that this topic has been studied for a long time, some issues require clarification. This paper examines the effect of the nacelle and jet of turbojet on the a wake vortex of aircraft. The paper provides a detailed introduction and well describes calculation methods. A good validation of the numerical data with the experimental results was carried out. But there are several significant shortcomings in the results of the work.
1) No figure 3.
2) Where is the origin of coordinates? Where are the axes pointing? The quantities y and z are indicated in what units in the figures?
3) In Fig. 7-8 there is clearly confusion with the arrangement of the data. For example, in Fig. 7 there is a caption - nacelle vortex, but this figure represents data for - “wake vortex without nacelles”. In this regard, it is difficult to read the text describing these figures.
4) How is circulation calculated in Fig. 9 and 14? At what distance from the vortex?
5) Why does the circulation increase at x/b = 20 (Fig. 9 and 14). Is this the vortex fusion point?
6) Does the gas flow rate through the engine in Chapter 3.3 change when the jet temperature changes?
7) Why is it the effect of engine jet temperature that is being studied, and not gas flow rate? What does it mean: "medium and strong jet being ideal" (line 396)? What is meant by ideal flow?
8) Where this conclusion comes from: “The increase of the jet intensity has a significant impact on the position of the vortex system, and the flattail trajectory gradually rises in the 20x to 50x wingspan region and gradually shifts away from the symmetry plane” (line 449-452).
From the reviewer's point of view from Figure 14, there is no significant effect of the engine jet. The position of the flat-tail vortex in the far wake changes by a maximum of 25%.
The conclusions of the article also need to be changed.
Conclusion (b) has not been confirmed; the paper does not provide quantitative data for the case of 4 degrees. Figure 6 only allows us to consider the structure of the vortex, but does not allow us to perform a quantitative assessment.
Conclusion (c) is controversial. There is no need to talk about a significant impact. From Fig. 14 shows that the position of the vortex changes by no more than 25%. And the circulation of the vortex remains unchanged. It is advisable to redo this conclusion.
Although conclusion (e) is logical, the paper does not provide the results that confirmed it. It is necessary to add results proving the correctness of this conclusion.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsMinor corrections:
1. line 89 "above the ground"
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsManuscript Number: aerospace-2979018-v2
Old Title: Study on the Influence of Powered Nacelle on the Wake Vortex Characteristics of Wide-Body
New Title: Study on the Influence of Powered Nacelle on the Wake Vortex Characteristics of Wide-Body Aircraft
The original text of the manuscript has been satisfactorily revised by authors. In my opinion, the manuscript can be published in Aerospace.
Comments on the Quality of English LanguageEnglish language and style are fine/minor spell check required. It is necessary to check form and style of text when examining the manuscript proof.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for Authors
The new version of the paper is more understandable for the reader than the original. But some points in the paper remain unclear:
1) After reading the second version of the paper, the reviewer became confused about the numerical methodology used. After reading the first version of the paper, the impression was that RANS is used only for the near-field region. But after reading the new version, it seems that the entire region is being calculated based on RANS. The reviewer is confused where LES modeling is used. The final paragraph in the conclusions of the article does not clarify the situation. In Chapter 2, it is necessary to clearly explain the approach to calculating the vortex behind an aircraft.
2) The increase in circulation remains unclear for all cases at x/b = 20 (Fig. 14c and Fig. 19c). If this is due to the merge of the wingtip vortex and the flat tail vortex, then the circulation should decrease, since these vortices should have opposite rotation. In addition it is not clear why graph 14c does not show the merging of vortices that occurs at x/b=31.7 without a nacelles (Fig. 12b) and x/b=11.8 (Fig. 13a) with the presence of an engine nacelles. It is worth clarifying this point in the text of the paper.
3) It is advisable to add gas mass flow rates through the engine to Table 5 in the paper.
Author Response
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Author Response File: Author Response.pdf
