Effect of Lateral End Plates on Flow Crossing a Yawed Circular Cylinder
Round 1
Reviewer 1 Report
The authors investigated the effect of the boundary condition of two lateral end-plate walls on flow structure in the wake of flow crossing a yawed circular cylinder. Numerical simulation with LES approach was used. The simulation results were compared with experimental data to verified the approach, and the results showed a good agreement with the previous study. Even though the recent results are in good agreement, I do not see any originality of this paper. What is originality? Please emphasize the originality of this recent paper, especially in the introduction section. Also, please explain more about the numerical method. Did the author develop in-house CFD code? Or was commercial CFD software used in this paper?
As a general comment, the reviewer believes that this paper needs a revision before it meets the standards for publication in an important international journal. The reviewer hopes that the detailed comments given below are useful.
1. Page 2, please check the Reynolds number equation in the nomenclature.
2. Page 3, please check the Eq. number. It should be aligned on the right.
3. I found inconsistent reference number in Fig. 2. Please revise the figure. Also, please re-check all references number.
4. Please give the reason why did authors choose three yaw angles (15°, 30°, and 45°)?
5. It seems that Fig. 4(b) and Fig. 4(c) is swapped. Is it true?
6. In Fig. 9, the cylinder length is shorter than in Fig. 8. Please, re-plot a streamline for periodic boundary condition similar to Fig. 8. Therefore, it is easier for readers to compare the results.
Author Response
Review Report Form 1
Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | ( ) | (x) | ( ) | ( ) |
Is the research design appropriate? | ( ) | (x) | ( ) | ( ) |
Are the methods adequately described? | ( ) | (x) | ( ) | ( ) |
Are the results clearly presented? | (x) | ( ) | ( ) | ( ) |
Are the conclusions supported by the results? | (x) | ( ) | ( ) | ( ) |
Comments and Suggestions for Authors
1- The authors investigated the effect of the boundary condition of two lateral end-plate walls on flow structure in the wake of flow crossing a yawed circular cylinder. Numerical simulation with LES approach was used. The simulation results were compared with experimental data to verified the approach, and the results showed a good agreement with the previous study. Even though the recent results are in good agreement, I do not see any originality of this paper. What is originality? Please emphasize the originality of this recent paper, especially in the introduction section. Also, please explain more about the numerical method. Did the author develop in-house CFD code? Or was commercial CFD software used in this paper?
Answer:
l On the originality of this research, it can be condensed on two points comparing with the previous works. Firstly, the boundary condition of the endplates of a yawed cylinder is generalized into two types with regards to industrial applications. Secondly, the effect of the boundary condition of two end plates on the wake flow as incoming flow crosses a yawed cylinder is thoroughly investigated, respectively inspecting the shedding vortex pattern, streamline change, pressure distribution on the surface of a cylinder, and frequency spectral of local lift coefficient at the two types of the boundary condition on the two endplates. These investigations have not yet appeared in the previous works. The introduction has been wholly rephrased with regards to the reviewers’ comments.
l Brief explanation of the numerical method ( LES turbulent model used in the paper) has been added in Section 2, seen in Lines 143-159.
l The CFD code in this paper is developed based on open source CFD software OpenFOAM®, seen in Lines 133-134.
As a general comment, the reviewer believes that this paper needs a revision before it meets the standards for publication in an important international journal. The reviewer hopes that the detailed comments given below are useful.
2- Page 2, please check the Reynolds number equation in the nomenclature.
It is corrected.
3- Page 3, please check the Eq. number. It should be aligned on the right.
It is corrected.
4- I found inconsistent reference number in Fig. 2. Please revise the figure. Also, please re-check all references number.
It is corrected.
5- Please give the reason why did authors choose three yaw angles (15°, 30°, and 45°)?
Considering that the crosswise component of velocity over a cylinder should be dominated over the in-line component of velocity, yaw angle of a cylinder in this research is therefore chosen not greater than 45°. Three yaw angles, respectively 15°, 30°, and 45°，corresponding to small, medium and larger yaw angle, are chosen for exploring the effect of yaw angle on the wake flow. Seen in Lines 98-101.
6- It seems that Fig. 4(b) and Fig. 4(c) is swapped. Is it true?
Yes, it is. It has been corrected.
7- In Fig. 9, the cylinder length is shorter than in Fig. 8. Please, re-plot a streamline for periodic boundary condition similar to Fig. 8. Therefore, it is easier for readers to compare the results.
The span width of computational domain is taken different for the two types of boundary condition, respective 9D and 6D for non-slip and periodic boundary conditions on the end plates. The reason is given in beginning of Section 2, mainly considering saving computational resource but without loss of the nature of wake flow. That is why the cylinder length in Figure 9 is shorter than in Figure 8. Seen in Lines 117-121
Submission Date
12 March 2019
Date of this review
20 Mar 2019 08:31:33
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper uses LES to study the effect of two boundary conditions (no-slip and periodic) of lateral end plates on the flow structures in the wake of flow crossing a yawed circular cylinder at three cylinder yaw angles. The information provided is sufficient and comprehensive, including vortex structure, streamline analysis, pressure distribution, spectral power and lift force. This paper can be accepted for publishing in the journal of Applied Sciences after some modifications. Please consider the following comments.
1. The reference lumps (1-4 and 6-10) are unacceptable. Please rephrase by adding an individual description for each reference.
2. The research gap of the previous studies should be addressed more clearly and systematically.
3. Regarding the computational methodology, the authors should indicate what software or code they use for simulation. Mesh independence should be proved with results, and is the mesh resolution sufficient for LES modeling? Mention more information on the chosen mesh, e.g. size and quality.
4. Figure 4 is hard to interpret. Do the authors mistake Figure 4b and Figure 4c? Why the yaw angle in Figure 4b looks larger than that in Figure 4c?
5. The readability of some Figures (4~6) can be improved by re-drawing with the aid of professional post-processing software.
6. In page 11, line 241, avoid using colloquial words, such as “we think”.
7. The authors should ask a native English speaker to help improve the language of the paper.
Author Response
Review Report Form 2
Open Review
( ) I would not like to sign my review report
(x) I would like to sign my review report
English language and style
( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | ( ) | (x) | ( ) | ( ) |
Is the research design appropriate? | ( ) | (x) | ( ) | ( ) |
Are the methods adequately described? | ( ) | ( ) | (x) | ( ) |
Are the results clearly presented? | ( ) | (x) | ( ) | ( ) |
Are the conclusions supported by the results? | (x) | ( ) | ( ) | ( ) |
Comments and Suggestions for Authors
This paper uses LES to study the effect of two boundary conditions (no-slip and periodic) of lateral end plates on the flow structures in the wake of flow crossing a yawed circular cylinder at three cylinder yaw angles. The information provided is sufficient and comprehensive, including vortex structure, streamline analysis, pressure distribution, spectral power and lift force. This paper can be accepted for publishing in the journal of Applied Sciences after some modifications. Please consider the following comments.
1. The reference lumps (1-4 and 6-10) are unacceptable. Please rephrase by adding an individual description for each reference.
The introduction has been wholly rephrased as the reviewer suggested. Each reference cited in the paper has been individually given a description.
2. The research gap of the previous studies should be addressed more clearly and systematically.
The research gap of the previous studies has been added and emphasized in the introduction. Seen in Lines 88-90.
3. Regarding the computational methodology, the authors should indicate what software or code they use for simulation. Mesh independence should be proved with results, and is the mesh resolution sufficient for LES modeling? Mention more information on the chosen mesh, e.g. size and quality.
The CFD code in this paper is developed based on open source CFD software OpenFOAM®. seen in Lines 133-134.
Mesh independence is added in the revision in Section 2, shown in Table 1. Seen in lines 171-188 and Table 1.
4. Figure 4 is hard to interpret. Do the authors mistake Figure 4b and Figure 4c? Why the yaw angle in Figure 4b looks larger than that in Figure 4c?
Figure 4b and Figure 4c is indeed mistakenly swapped in the previous version. In the revision, it is corrected.
5. The readability of some Figures (4~6) can be improved by re-drawing with the aid of professional post-processing software.
Figures 4-6 are post-processed by TecPlot.
6. In page 11, line 241, avoid using colloquial words, such as “we think”.
It is rephrased.
7. The authors should ask a native English speaker to help improve the language of the paper.
As the reviewers suggested, the paper has been edited by a professional native speaker.
Submission Date
12 March 2019
Date of this review
19 Mar 2019 06:26:27
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors have studied the Effect of Lateral End Plates on Flow Crossing a Yawed Circular Cylinder. It is an exciting piece of research, and my overall recommendation is in favor to publish the paper. However, there are some points which need to be addressed before the publication as follows:
1- The quantitative results should be mentioned in the Abstract
2- Nomenclature should include the unit of parameters
3- The introduction should be the more elaborate highlighting theist of importance of the subject, very salient previous research work and the need of the present work. Besides, the author can also include the following articles:
-Hydrothermal analysis of turbulent boehmite alumina nanofluid flow with different nanoparticle shapes in a minichannel heat exchanger using two-phase mixture model.
-Comparison of the effect of five different entrance channel shapes of a micro-channel heat sink in forced convection with application to cooling a supercomputer circuit board.
-Investigation of a computer CPU heat sink under laminar forced convection using a structural stability method.
4- It would be better for the authors to highlight the state of the art of the study in the last paragraph in the introduction section.
5- Please add a Table that shows mesh independence investigation with the difference in %.
6- All the parameters that have been used in this paper should be non-dimensional.
7- In section 3.4 (Fig 13 - Frequency Spectra of local Lift coefficient) the author must explain why the lift coefficient for non-slip boundary has reverse characteristics from 0 to 60-time period compare to periodic boundary conditions?
Good Luck
Author Response
Review Report Form 3
Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
English language and style
( ) Extensive editing of English language and style required
(x) Moderate English changes required
( ) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | ( ) | (x) | ( ) | ( ) |
Is the research design appropriate? | (x) | ( ) | ( ) | ( ) |
Are the methods adequately described? | (x) | ( ) | ( ) | ( ) |
Are the results clearly presented? | (x) | ( ) | ( ) | ( ) |
Are the conclusions supported by the results? | (x) | ( ) | ( ) | ( ) |
Comments and Suggestions for Authors
The authors have studied the Effect of Lateral End Plates on Flow Crossing a Yawed Circular Cylinder. It is an exciting piece of research, and my overall recommendation is in favor to publish the paper. However, there are some points which need to be addressed before the publication as follows:
1- The quantitative results should be mentioned in the Abstract
The results in the research is up to now still in the qualitative phase. In the next step, our research will be turned to quantitative analyses, e.g. given the curves to depict the dependence of the two peak frequencies on Reynolds number and yaw angle, and etc.
2- Nomenclature should include the unit of parameters
It is added.
3- The introduction should be the more elaborate highlighting theist of importance of the subject, very salient previous research work and the need of the present work. Besides, the author can also include the following articles:
The introduction has been wholly rephrased as the reviewers suggested, in which the novelties of this work are emphasized. Meanwhile, recent relevant researches have been reviewed and added in the introduction.
-Hydrothermal analysis of turbulent boehmite alumina nanofluid flow with different nanoparticle shapes in a minichannel heat exchanger using two-phase mixture model.
-Comparison of the effect of five different entrance channel shapes of a micro-channel heat sink in forced convection with application to cooling a supercomputer circuit board.
-Investigation of a computer CPU heat sink under laminar forced convection using a structural stability method.
4- It would be better for the authors to highlight the state of the art of the study in the last paragraph in the introduction section.
It is added in the last two paragraphs in the introduction section.
5 Please add a Table that shows mesh independence investigation with the difference in %.
It is added.
Mesh independence is added, as shown in Table 1.
6 All the parameters that have been used in this paper should be non-dimensional.
All the parameters in the paper are indeed non-dimensionalized, as shown in the start of Section 2. Seen in Lines 111-112.
7 In section 3.4 (Fig 13 - Frequency Spectra of local Lift coefficient) the author must explain why the lift coefficient for non-slip boundary has reverse characteristics from 0 to 60-time period compare to periodic boundary conditions?
There is no intrinsic relevance between them. They result from separate calculation cases. Put them together is just to compare their amplitude.
Good Luck
Submission Date
12 March 2019
Date of this review
15 Mar 2019 17:49:32
Author Response File: Author Response.pdf
Reviewer 4 Report
The English language should be revised be a native.
Please add a period (.) at the end of the keywords.
Some Nomenclatures do not have units.
Figure 2: All three mentioned references are wrong! There are just 23 references in the manuscript, not 24!
Please indicate the mesh-independency study in the manuscript.
Please withdraw figures 11 & 12, again as they are not clear.
All references except 10 and 13 are very old, and therefore, they are abolished. May the reviewer ask the authors to change these references to newer ones? Some suggested references are as below:
https://www.sciencedirect.com/science/article/pii/S0997754616303223
https://aip.scitation.org/doi/abs/10.1063/1.5079750
https://www.sciencedirect.com/science/article/pii/S0029801818301355
https://www.tandfonline.com/doi/abs/10.1080/10407790.2015.1012440
https://www.sciencedirect.com/science/article/pii/S0889974615002212
https://brage.bibsys.no/xmlui/handle/11250/2480466
Please make some citations for governing equations.
Line 70 should be merged with line 69.
What is the real application of present study?
What is/are the novelty(ies) of your work, compared to similar published previous works?
Author Response
Review Report Form 4
Open Review
(x) I would not like to sign my review report
( ) I would like to sign my review report
English language and style
( ) Extensive editing of English language and style required |
Yes | Can be improved | Must be improved | Not applicable | |
Does the introduction provide sufficient background and include all relevant references? | ( ) | ( ) | (x) | ( ) |
Is the research design appropriate? | ( ) | (x) | ( ) | ( ) |
Are the methods adequately described? | ( ) | (x) | ( ) | ( ) |
Are the results clearly presented? | ( ) | ( ) | (x) | ( ) |
Are the conclusions supported by the results? | (x) | ( ) | ( ) | ( ) |
Comments and Suggestions for Authors
1 The English language should be revised be a native.
As the reviewers suggested, the paper has been edited by a professional native speaker.
2 Please add a period (.) at the end of the keywords.
It is added.
3. Some Nomenclatures do not have units.
Units are added in the nomenclature.
4. Figure 2: All three mentioned references are wrong! There are just 23 references in the manuscript, not 24!
It is corrected.
5. Please indicate the mesh-independency study in the manuscript.
Mesh-independency has been added, as shown in Table 1 in Section 2.
6. Please withdraw figures 11 & 12, again as they are not clear.
Figures 11 & 12 are redrawn. They have been outputted with finer resolution.
7. All references except 10 and 13 are very old, and therefore, they are abolished. May the reviewer ask the authors to change these references to newer ones? Some suggested references are as below:
We are very appreciated to this respectful reviewer. The papers of Zeinoddini et al 2015, Pierson et al 2017, Shadloo et al 2018 and Wang et al 2019 has been cited, which are very relevant to this work.
https://www.sciencedirect.com/science/article/pii/S0997754616303223
https://aip.scitation.org/doi/abs/10.1063/1.5079750
https://www.sciencedirect.com/science/article/pii/S0029801818301355
https://www.tandfonline.com/doi/abs/10.1080/10407790.2015.1012440
https://www.sciencedirect.com/science/article/pii/S0889974615002212
https://brage.bibsys.no/xmlui/handle/11250/2480466
1. Please make some citations for governing equations.
It has been added. And meanwhile the LES model used in this work is also given some brief description
2. Line 70 should be merged with line 69.
It has been in line.
3. What is the real application of present study?
The present study is triggered by our practical engineering design of helical-tube steam generators in nuclear reactors. We need the prediction of the wake flow to evaluate the induced vibration as incoming flow sweeps helically-wound heat-transfer tubes.
4. What is/are the novelty(ies) of your work, compared to similar published previous works?
On the novelties of this work, it can be condensed on two points comparing with the previous works. Firstly, the boundary condition of the endplates of a yawed cylinder is generalized into two types with regards to industrial applications. Secondly, the effect of the boundary condition of two end plates on the wake flow as incoming flow crosses a yawed cylinder is thoroughly investigated, respectively inspecting the shedding vortex pattern, streamline change, pressure distribution on the surface of a cylinder, and frequency spectral of local lift coefficient at the two types of the boundary condition on the two endplates. These investigations have not yet appeared in the previous works. The introduction has been rephrased with regards to the reviewers’ comments.
Submission Date
12 March 2019
Date of this review
15 Mar 2019 05:02:24
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
This revision has corrected all the previous issues suggested by the reviewer, and now it is acceptable for publication.
Reviewer 4 Report
Accept as is.
