Research on Drag Reduction by Coating the Inner Wall of Hydraulic Pipeline
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis study aims to perform numerical simulations using computational fluid dynamics to investigate the effect of wall roughness on linear loss in circular pipelines.
It is purely a theoretical work. Apart from a small typographical error, frankly, there are no serious deficiencies in terms of both English grammar and content. This may be related to the existence of similar works by the authors, that is, their real mastery of the field.
Comments for author File: 
Comments.pdf
It is quite good.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authorsplease see attached document
Comments for author File: Comments.pdf
Even for a non-native English speaker like myself, the paper needs a thorough English revision
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper presents a study focused on reducing head losses in pressure pipelines through the application of coatings. Despite the relevance of the topic, in my opinion, the study suffers from significant shortcomings that undermine its validity.
The primary concern with this study is that in relies only on CFD simulations without any experimental validation. CFD simulations results can be valuable but their results must be in line with experimental data to ensure accuracy. The absence of the experimental results makes it difficult to asses the practical applicaibility of the findings.
The authors use the term "roughness elements". I thnik this is a bit confusing because the "wall roughess" usually refers to average height of surface regularities of a pipe wall material rather than distinct elements. I am not sure if the authors' terminology is in line with standard definitions in this field of research.
The study presents the effect of different coating heights on pressure loss reduction but fails to provide reason why the exact pattern of the "rougness elements" was chosen. The arbitrary selection of this pattern without any explenation raises questions about the relevance of the findings.
Another major limitation is that the authors analysed only a single pipe geometry. The generalizability of the results is questionable given the narrow scope of the study. Findings should be applicable to a broader range of pipelines geometries.
The manuscript also contains several technical flaws. There are numerous missing descriptions of symbols in mathematical formualas, I found some typos and figures that are not referenced in the text. This suggests a lack of attention to details in the preperation of the manuscript.
To improve this study I recommend major revisions. I suggest:
- Extend the analysis to expand the scope to include multiple pipeline geometries.
- Provide a clear explenation for the chosen pattern of roughness elements (maybe analyse more patterns).
- Explain the terminology and align it with standard definitions used in pipeline hydraulics.
-Improve manuscript quality.
- Ideally, conduct some experiments to validate CFD results. The authors' track record shows that they have the ability to conduct relevant experiments.
Comments on the Quality of English LanguageThe article contains typos and omissions that indicate that the manuscript was not prepared with due care.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsIn the manuscript entitled " Research on drag reduction by coating the inner wall of hydraulic pipeline", the effect of wall roughness on linear loss in circular pipelines was investigated by numerical simulation using computational fluid dynamics (CFD). It is an important theoretical basis for friction reduction and pipeline design optimization research by analyzing the effect of these parameters on flow characteristics through numerical simulations. Research findings reveal that the pressure difference at both ends of the pipeline decreases as the distance between roughness units increases. It has been shown that increasing the height of the roughness elements by 2 mm intervals leads to high differential pressure and there is a direct relationship between roughness size and linear loss. Applying nickel plated coating to the interior wall surface has been reported to reduce linear loss by reducing wall roughness.
Novel theoretical approaches were made in the study and originality was carried out to be increased. However, the corrections and additions listed below must be made.
1. Table 1 given on line 171 is not mentioned in the text.
2. The term "El" in Equation 1 needs to be defined in the text. In addition, how and by whom this equation was derived should be referenced, if necessary.
3. Are the model given in Figure 2 and the model dimensions given starting from line 162 standard? What is the basis for size selection? What are the effects on your results?
4. The purpose and intention of discussing the plating mentioned in the title and the Nickel plated coating details mentioned in the text are the most important shortcomings. The purpose of specified coating in the study, the method and the coating selection should be detailed and discussed in detail in the article.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsThank you for addressing my suggestions. I have no further comments.
Author Response
Dear reviewers,
We hope this message finds you well. We sincerely thank you for your time and effort to review our manuscript. Your feedback is invaluable and has greatly contributed to improving our work.
We are particularly thankful for your constructive comments and suggestions, which have provided clear guidance on areas that require further development and clarity. Your insights have allowed me to address several key aspects of the manuscript, and we believe these revisions have strengthened the overall quality of the work.
Your thorough review and thoughtful suggestions were instrumental in enhancing the depth and clarity of the research. We have carefully considered your feedback and made the necessary revisions to address your comments comprehensively. I am confident that the revised manuscript is now more robust and clearer in its contributions.
Once again, thank you for your meticulous review and constructive feedback. Your expertise and guidance are greatly appreciated, and we look forward to the possibility of our manuscript being accepted for publication.
Best regards.
Reviewer 4 Report
Comments and Suggestions for AuthorsIn the manuscript entitled "Research on drag reduction by coating the inner wall of hydraulic pipeline", the corrections requested and the responces given in the first revision were found sufficient. The article is acceptable in its current state.
Author Response
Dear reviewers,
We hope this message finds you well. We are writing to express my gratitude for your thorough and insightful review of our manuscript. Your detailed feedback and suggestions have been instrumental in guiding the revision process, and we sincerely appreciate the time and effort you dedicated to this task.
Your comments were extremely valuable in identifying key areas where the manuscript could be improved. Your constructive criticism helped us refine the methodology, clarify the interpretation of the results, and ensure that the overall research presentation is more robust and coherent.
Thank you once again for your invaluable feedback and for contributing to the refinement of this manuscript. We greatly appreciate your time and effort.
