Assessing the Meshing for Windage Power Loss Simulations of an Orthogonal Face Gear

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Please see attached document.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

For the most part, this read fine. I gave several suggestions in my review document.

Several uses of "the" could be removed throughout the document.

Author Response

Please see the attached file.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Manuscript title

 Assessing the meshing for windage power losses simulation of  an orthogonal face gear

Authors

Tiberiu-Daniel Pau, Zoltan-Iosif Korka, Dorian Nedelcu  and Corneliu Hrimiuc

 

 

Reviewer’s remarks

1. The research is developed on the works of Zhu, X. and Dai, Y. - references [14] and [15] - as well as on other previously published works by other authors who have treated the same topics. The study does not have fundamental theoretical or experimental contributions, while it evokes well-known theories and methods presented extensively by other authors.
2. The objective of the research is to study the influence of meshing on the accuracy of the results obtained through FEM analysis. The conclusion of the study, that with increasing level of mesh refinement, the accuracy of the numerical model also increases, is a natural and well-known principle. From this evidence, I consider that the objective of the work is marginal and does not actually address the substance of the phenomena. In fact, the paper is more a case study conducted with the aim of investigating the influence of meshing on FEM analysis.
3. The contribution of the study may be of methodological matter, showing the possibility of using software applications for finite element analysis of friction losses during gear operation, which are anyway a maximum of 1-3%.
4. The story of the importance of air friction losses is important in the case of high gear rotation speeds, not at 1000-3000 rpm, to which the model in the paper is applied.
   The study would gain value if it addressed phenomena at high speeds.
5. Regarding the results obtained, I believe that the error analysis that would validate the applied methods is missing.
6. I would recommend carefully checking the text, as I have identified drafting errors, for example, the graph in Figure 3 is “test gear” not “test stand”, and the caption of Figure 12.
7. Finally, I appreciate that the manuscript can be considered for publication after a major revision.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

English writing should be carefully checked to become more understandable.

Author Response

Please see the attached file.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The paper provides an interesting scientific study but some issues should be solved:

1. Please describe in Introduction in which practical applications of orthogonal face gears occur the windage power loses?
2. Fort the Theoretical background, please present relevant calculus sketches and drawings in order to identify the parameters used in the mathematical relations. Some relations are not related to the references ( (1) ... (4)). Please explain how they have been obtained.
3. Please include some realistic photos of the test stand and indicate its components and characteristics.
4. The paper talks about a gear but in 3. Materials and Methods is presented only a wheel. How realistic is a model which study the windage power loses of a toothed wheel? In which practical applications we may find a toothed wheel which is not transmitting a power but is placed in an air flow?
5. How have been established the cells numbers in Table 3?
6. What is the influence of computational resources form Figure 11 on the paper’s main objective (the windage power loses)?
7. The Conclusions are very weak.

• It is not relevant the number of 689605 cells used in the simulation. What about if you will use 689606? Or 689604? Same problem regarding the increasing of number of cells by 19.17 times.
• The conclusion regarding the discretization is a general one and can be applied for any FE model. Is not a relevant conclusion for your work.
• The last conclusions referring on the flow simulation software can be applied for any soft simulation software and is not relevant for your work.
• So please, redefine all the conclusions in order to be relevant for your scientific work.

 

Author Response

Please see the attached file.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Authors improved the paper and satisfied my review comments.

Author Response

Comment: Authors improved the paper and satisfied my review comments.

Answer: We would like to express our sincere gratitude to the reviewer for his valuable feedback, which has greatly contributed to the enhancement of our manuscript.

 Yours faithfully,

Zoltan KORKA et al.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors responded to all the reviewer's recommendations and, where appropriate, introduced additional information and explanations.
The authors also added discussions and comments, according to the reviewer's observations, so that the manuscript was completed and improved. The conclusions section was revised and enriched with new aspects resulting from the study.
Taking note of the improved version of the manuscript, I consider that the work can be considered for publication, after minor revision.

Comments on the Quality of English Language

The English wording can be improved to more accurately reflect the scientific content of the paper.

Author Response

Comments and Suggestions for Authors: The authors responded to all the reviewer's recommendations and, where appropriate, introduced additional information and explanations.

The authors also added discussions and comments, according to the reviewer's observations, so that the manuscript was completed and improved. The conclusions section was revised and enriched with new aspects resulting from the study.

Taking note of the improved version of the manuscript, I consider that the work can be considered for publication, after minor revision.

Answer: We would like to extend our sincere appreciation to the reviewer for his insightful comments, which have significantly enhanced the quality of our manuscript.

 Comments on the Quality of English Language: The English wording can be improved to more accurately reflect the scientific content of the paper.

Answer: We appreciate your observation. Following it, we consulted a native English speaker, and based on his suggestions, we made several adjustments to better represent the scientific content of the paper.

 

Yours faithfully,

Zoltan KORKA et al

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for the revised paper but some issues still should be solved:

1. Please include some realistic photos of the test stand and indicate its components and characteristics.
2. The paper talks about a gear but in 3. Materials and Methods is presented only a wheel. How realistic is a model which study the windage power loses of a toothed wheel? In which practical applications we may find a toothed wheel which is not transmitting a power but is placed in an air flow?

Author Response

Reviewer comment: Thank you for the revised paper but some issues still should be solved:

1. Please include some realistic photos of the test stand and indicate its components and characteristics.

Answer: We would like to extend our sincere appreciation to the reviewer for his insightful comments. We have revised Figure 2 and instead of showing the schematic of the test stand, we included the photo of the test stand used by Zhu and Dai [19] to measure the windage losses of the face gear. The insertion of the photo in our manuscript was done with the written approval of the editor of the journal in which the referenced article was published. In addition, we have indicated the main components of the stand and their technical characteristics, as they were available in the cited reference. All the changes made, compared to the previous revision, were marked in green.

2. The paper talks about a gear but in 3. Materials and Methods is presented only a wheel. How realistic is a model which study the windage power loses of a toothed wheel? In which practical applications we may find a toothed wheel which is not transmitting a power but is placed in an air flow?

Answer: Thank you for your comment. Indeed, there is no practical application, to which a toothed wheel is not transmitting power, but is placed in an airflow. However, it should be noted that windage power losses are independent of the transmitted power. This perspective, combined with our intention to develop a digital twin of a prior practical experiment, guided us in creating the model under the same experimental conditions. This methodology enabled us to conduct a thorough comparison between the simulation results and the experimental findings.

We hope that you are satisfied with our answers. Should you have any questions or considerations to make, please do not hesitate.

 Yours faithfully,

Zoltan KORKA et al.

Round 3

Reviewer 3 Report

Comments and Suggestions for Authors

Thank you for the revised paper.