Vortex Ring Theory—An Alternative to the Existing Actuator Disk and Rotating Annular Stream Tube Theories
Round 1
Reviewer 1 Report
The manuscript has been revised well compared to the original version submitted earlier this year. Therefore, it will be recommended to publish in Applied Sciences. There are some minor formatting errors the authors might need to correct them in the final manuscript.
Author Response
Dear Reviewer,
Thank you for taking time to review our paper. Your suggestions and comments have helped us to improve the quality of the paper. Our responses to your comments are written in bold italics.
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
The paper has been checked for grammatical and spelling errors. All errors have been corrected accordingly.
( ) 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? The introduction has been proofread and corrected for grammatical and spelling errors and all relevant references have been cited appropriately. |
( ) |
(x) |
( ) |
( ) |
|
Is the research design appropriate? |
( ) |
(x) |
( ) |
( ) |
|
The research design has been corrected to meet the standards of the journal.
Are the methods adequately described? |
( ) |
(x) |
( ) |
( ) |
|
The methodology has been updated to improve its lucidity. Are the results clearly presented? |
( ) |
(x) |
( ) |
( ) |
|
All the figures have been updated with better quality ones and the discussion of results has been appropriately updated. Are the conclusions supported by the results? |
( ) |
(x) |
( ) |
( ) |
The conclusions were checked for grammatical errors and revised accordingly.
Comments and Suggestions for Authors
The manuscript has been revised well compared to the original version submitted earlier this year. Therefore, it will be recommended to publish in Applied Sciences. There are some minor formatting errors the authors might need to correct them in the final manuscript.
Dear Sir/Madam, thank you for your positive review of our paper. All the formatting errors have been corrected accordingly.
Reviewer 2 Report
The present work concerns the study of HAWTs, in particular, the applicability of a version of the vortex ring theory (VRT). It is an important work which offers an improved and less computational expensive method to study emerging renewable energy technologies.
Notes:
- In section 1, an extensive and very complete introduction regarding commonly used methods and their applicability is presented.
- Sections 2 and 3 adequately describe the methods and their limitations.
- In methodology, the design parameters are indicated as well as the study regime.
- In results, the unit kilonewton should be written as kN instead of KN. Regarding results, strong evidence is given to demonstrate the applicability of each method in each regime.
- Some figures and equations seem to be not formatted.
This paper should be accepted after a minor revision.
Author Response
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
The paper has been checked for grammatical and spelling errors. All errors have been corrected accordingly.
( ) 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) |
( ) |
( ) |
( ) |
|
Dear Sir/ Madam, thank you for your positive review. Is the research design appropriate? |
(x) |
( ) |
( ) |
( ) |
|
Dear Sir/ Madam, thank you for your positive review. Are the methods adequately described? |
(x) |
( ) |
( ) |
( ) |
|
Dear Sir/ Madam, thank you for your positive review. Are the results clearly presented? |
( ) |
(x) |
( ) |
( ) |
|
Dear Sir/Madam, all the figures have been replaced with better quality ones and the discussion of results has been revised appropriately. Are the conclusions supported by the results? |
(x) |
( ) |
( ) |
( ) |
Dear Sir/ Madam, thank you for your positive review.
Comments and Suggestions for Authors
The present work concerns the study of HAWTs, in particular, the applicability of a version of the vortex ring theory (VRT). It is an important work which offers an improved and less computational expensive method to study emerging renewable energy technologies.
Notes:
- In section 1, an extensive and very complete introduction regarding commonly used methods and their applicability is presented.
Dear Sir/ Madam, thank you for your positive review.
- Sections 2 and 3 adequately describe the methods and their limitations.
Dear Sir/ Madam, thank you for your positive review.
- In methodology, the design parameters are indicated as well as the study regime.
- Dear Sir/ Madam, thank you for your positive review.
In results, the unit kilonewton should be written as kN instead of KN. Regarding results, strong evidence is given to demonstrate the applicability of each method in each regime
Dear Sir/ Madam, thank you for your positive review. The unit has been changed from KN to kN per your suggestion.
- Some figures and equations seem to be not formatted.
All the graphs have been replaced with better quality ones and the entire paper and equations have been formatted to palatino linotype font size 10 as required by the journal.
This paper should be accepted after a minor revision.
Dear Sir/ Madam, thank you for your positive review.
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
Is the boundary layer on the blades actually laminar (line 110)? Turbine blades get dirty...
The many acronyms used make reading the article more difficult. Consider using the full name of the method instead.
A derivation of the actuator disk theory is not necessary, it is to be found in any textbook.
A description of the specific MATLAB plot commands (from line 611) is not really interesting.
A further spelling check could be useful (e.g. "caparison" instead of "comparison", line 677). Do not put commas after "that", for example, correct "...the assumption that, the velocity deficit..." into "...the assumption that the velocity deficit..."
The comparison in figure 11 should include the results from conventional methods. It does not give a clear impression of the advantage of the proposed method.
Author Response
Dear Reviewer,
Thank you for reviewing our article. Your comments have greatly enhanced the improvement of this article. Our responses to your comments are in bold, italicized characters. Please all the changes made to the article are in red characters.
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? |
( ) |
( ) |
( ) |
( ) |
|
Are the conclusions supported by the results? |
( ) |
( ) |
( ) |
( ) |
Comments and Suggestions for Authors
Is the boundary layer on the blades actually laminar (line 110)? Turbine blades get dirty...
This assertion is made by the reference cited. It is not a claim made by the authors. To shed some light boundary layer theory is a turbulent flow theory as could be seen from the works of Professor Blasius. Even if the turbine blade gets dirty the dirt on the blade will increase the roughness of the surface of the blade, increasing skin friction and reducing slip along the blade. The laminar boundary layer is an idealization, made in a bid to solve turbulent flow problems.
The many acronyms used make reading the article more difficult. Consider using the full name of the method instead.
The full names of the theories have been used as recommended.
A derivation of the actuator disk theory is not necessary, it is to be found in any textbook.
The derivation of both the actuator disk and rotating annular stream tube theories have been removed as recommended.
A description of the specific MATLAB plot commands (from line 611) is not really interesting.
The MATLAB commands have been deleted as recommended.
A further spelling check could be useful (e.g. "caparison" instead of "comparison", line 677). Do not put commas after "that", for example, correct "...the assumption that, the velocity deficit..." into "...the assumption that the velocity deficit..."
The entire sentence has been deleted. All spellings have been checked for correctness.
The comparison in figure 11 should include the results from conventional methods. It does not give a clear impression of the advantage of the proposed method.
The results of the conventional methods have been included in the figure as recommended.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript is about using the vortex ring theory to predict rotor performance. The topic is interesting but it seems to the reviewer that the present manuscript is too long and it looks like it is a modified version of a PhD/MSc thesis. Specific comments are given below.
1) There are many formatting mistakes in the manuscript. The authors should read the manuscript thoroughly before submission. In addition, some writing in the introduction is kind of informal. For example in line 147 'Digressing a bit, it is worth to note that...' apparently is not something that commonly appeared in academic publications. The authors should make sure formal writing is used throughout the manuscript.
2) The introduction is too long. In fact, it is 3 pages long but actual useful information given in the section is limited. The reviewer would suggest the authors to shorten the introduction to 1 to 1.5 page as it is a bit boring to read.
3) Similar to point 2, Sub-sections 2.1 and 2.2 are not really necessary. They are just the general ADT and RAST and hence, those equations shown in these subsections can be found in textbooks or published literatures and hence, it would be great if the authors just reference those publications instead of reproduce all of the equations for these theories again. Similarly, the authors should shorten subsection 2.3 for those equations from the standard vortex ring theory.
4) Methodology has to be strengthened. There is no need to tell people what Matlab commands were used to plot graphs but more detailed information about the experimental and numerical study should be given. Although the authors have cited a publication which includes this information, it is still a good practice to outline the experimental and numerical set up in the present manuscript.
5) In the results and discussion, the authors did compare the results from VRT with those from RAST and ADT, it is unclear which theory actually gives the most accurate result. To be exact, it seems to the reviewer that some validation process should be included to prove the accuracy of the newly developed theory.
6) The authors did compare the results predicted by the newly developed theory with existing numerical and experimental data. However, the results predicted by the theory do not seem agree well with those numerical or experimental data. This means that how could we tell the theory developed is correct and accurate enough to be used to evaluate the wind turbine performance?
The authors should address all the above points in the revised manuscript.
Author Response
Dear Reviewer,
Thank you for reviewing our article. Your comments have greatly enhanced the improvement of this article. Our responses to your comments are in bold, italicized characters. Please all the changes made to the article are in red characters.
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?
The introduction has been improved per your recommendation. |
( ) |
(x) |
( ) |
( )
|
|
Is the research design appropriate? |
( ) |
( ) |
(x) |
( ) |
|
The research design has been improved as recommended. Are the methods adequately described? |
( ) |
( ) |
(x) |
( ) |
|
The methods have been adequately improved. Are the results clearly presented? |
( ) |
( ) |
(x) |
( ) |
|
The presentation of the results has been improved accordingly.
Are the conclusions supported by the results? |
( ) |
(x) |
( ) |
( ) |
The conclusions have been adequately improved to support the results.
Comments and Suggestions for Authors
The manuscript is about using the vortex ring theory to predict rotor performance. The topic is interesting but it seems to the reviewer that the present manuscript is too long and it looks like it is a modified version of a PhD/MSc thesis. Specific comments are given below.
- There are many formatting mistakes in the manuscript. The authors should read the manuscript thoroughly before submission. In addition, some writing in the introduction is kind of informal. For example in line 147 'Digressing a bit, it is worth to note that...' apparently is not something that commonly appeared in academic publications. The authors should make sure formal writing is used throughout the manuscript.
All the formatting errors have been corrected. The sentence in line 147 has been changed to read, “ It is worth noting”.
- The introduction is too long. In fact, it is 3 pages long but actual useful information given in the section is limited. The reviewer would suggest the authors to shorten the introduction to 1 to 1.5 page as it is a bit boring to read.
The introduction is adequate, and all the references cited are relevant to the article.
- Similar to point 2, Sub-sections 2.1 and 2.2 are not really necessary. They are just the general ADT and RAST and hence, those equations shown in these subsections can be found in textbooks or published literatures and hence, it would be great if the authors just reference those publications instead of reproduce all of the equations for these theories again. Similarly, the authors should shorten subsection 2.3 for those equations from the standard vortex ring theory.
These subsections have been eliminated and only relevant eauations from these theories have been used.
- Methodology has to be strengthened. There is no need to tell people what Matlab commands were used to plot graphs but more detailed information about the experimental and numerical study should be given. Although the authors have cited a publication which includes this information, it is still a good practice to outline the experimental and numerical set up in the present manuscript.
The methodology has been adequately strengthened and all the MATLAB commands have been removed from the article. The issue of the methods used in the previous paper is not necessary since the source has been cited. Also this is not necessary because it will make the paper to be too long.
- In the results and discussion, the authors did compare the results from VRT with those from RAST and ADT, it is unclear which theory actually gives the most accurate result. To be exact, it seems to the reviewer that some validation process should be included to prove the accuracy of the newly developed theory.
It is clearly stated on the article that the vortex ring theory better predicts the flow physics of the wind turbine. This is an analysis-based paper and not an experimental paper of CFD based paper where issues of precision are not feasible. The curves of the conventional theories and the VRT have been plotted with those of existing numerical and experimental data as shown on Figure 9 IN the paper.
- The authors did compare the results predicted by the newly developed theory with existing numerical and experimental data. However, the results predicted by the theory do not seem agree well with those numerical or experimental data. This means that how could we tell the theory developed is correct and accurate enough to be used to evaluate the wind turbine performance?
Even then the existing numerical results are higher than the existing experimental results even though the two curves have upward concavity. The new theory follows the same trend as the previous two curves. Similarly, the ADT follows the same trend even though the ADT values are lower than all the other three curves. It has been adequately demonstrated the new theory is reliable and can accurately evaluate the performance of wind turbines.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
this version is acceptable to me
