Study on Propulsion Performance by Varying Rake Distribution at the Propeller Tip
Round 1
Reviewer 1 Report
The paper has excellent contents, good presentation of the results.
I suggest the author presents a summary table comparing the results of the measurements and modelling derived both from the potential code and the FVM code. The readers will appreciate a clear picture of how the two numerical methods compare.
The authors should also include more information on the numerical models, geometric information of the propellers and the model setup. This article will be very useful to graduate students, so more information on the propellers, models and measured data in tabular form will be invaluable to students.
The author should discuss the uncertainty of the measurement's and the numerical results. Grid dependency and timestep sensitivity study should be done for both numerical methods and a summary should be presented in the article.
The authors should try to comply with the above advices, which will improve the quality of the article and get a high rank for the overall merit.
Author Response
Thank you for your kind review for the my paper.
Please see the attachment of response to your comments.
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Reviewer 2 Report
Line 11: Add an article "a" before significant interest.
Line 14: Replace "tip vortex" and "tip cavity" with tip vortex cavitation.
Line 79: Remove the word "as" from "is as shown".
Line 99: Replace "finaly" with "final".
Line 160: All symbols should be in italics and should follow what has been referred to in the equations.
Line 161: Again, the symbols should be in italics.
Other comments:
Figure 2 is not clearly visible. The figures could be enlarged.
Figures 4, 6, 8 and 9 show the labels in italics compared to what has been shown in figures 12 and 14.
All figures should be generated and not copied from other sources.
Too much information has been attempted to discuss. So, a little more length of the paper may help in ease of understanding for the reader.
The paper could be improved in it overall presentation and clarity.
Author Response
Thank you for your kind review for the my paper.
Please see the attachment of response to your comments.
If there is any additional comments, please review again.
Author Response File: Author Response.pdf
Reviewer 3 Report
The present study provides a comparison of propulsion performance, with a particular focus on efficiency, by varying rake distribution at the tips of marine propellers. Because of increased attention to environmental pollution, there is significant interest in reducing EEDI and SOx emissions by improving of watercraft and ships. The forward (KAPPEL) and backward tip rake propellers have been widely used to improve efficiency, as well as to reduce fluctuating pressure from the tip vortex and tip cavity. As there is almost no parametric and design research on tip rake propellers, this systematic parametric study was conducted to identify the optimum configuration by using potential flow hydro code. For this performance comparison the KP505 (KCS propeller) was chosen as the reference propeller as the tips of that propeller have no rake. The model test and CFD calculation confirmed the result by comparing the open water performances for the three optimally selected propellers (forward, backward, KP505). The differences of efficiency obtained from the potential flow analysis and the model test exhibit similar tendencies, but the result observed in the CFD is different. The difference should be investigated by changing the grid system around the tip as well as the turbulence model in the CFD analysis before accepting the paper for publication.
The authors should also improve their English. Finally minor details like showing the sense of propeller rotation e.g. in Fig. 3, 11, 13 etc. will greatly improve the presentation of their work.
Author Response
Thank you for your kind review for the my paper.
Please see the attachment of response to your comments.
If there is any additional comments, please review again.
Author Response File: Author Response.pdf
