Blade Twist Effects on Aerodynamic Performance and Noise Reduction in a Multirotor Propeller
Round 1
Reviewer 1 Report
The manuscript entitled “Blade Twist Effects on Aerodynamic Performance and Noise Reduction in A Multirotor Propeller” by Sun et al. has been reviewed. The manuscript presents a study that investigates the impact of blade twist angle on the aerodynamic and acoustic performance of multirotor propellers. Both experimental measurements and computational fluid dynamic (CFD) simulations were utilized to compare the performance and noise reduction of twisted and untwisted blades. The study used 2D phase-locked particle image velocimetry (PIV) to visualize flow structures at specific blade locations. The manuscript requires some revisions before it can be acceptable for publication. Please consider the following comments:
The abstract needs to be modified and explain briefly the novelty of the work.
You need to provide insight into the unique contributions of this work that differentiate it from prior research and finding. This needs to be clearly highlighted and discussed in the paper.
Abbreviations are not recommended for use in the abstract. Also, given the numerous acronyms and abbreviations utilized throughout the manuscript, the inclusion of a nomenclature would greatly aid in clarity and comprehension.
The proposed integrated platform for evaluating the aeroacoustics performance of multirotor propellers is a valuable contribution to the field, and the findings of the study could be useful for improving the aerodynamic and acoustic performance of small-scale UAVs. However, it requires substantial and comprehensive revisions. to incorporate the key findings and results from prior investigations, with greater emphasis on providing specific details regarding those findings.
What type of material was selected for the fabrication of the propeller, and what are its specific characteristics? In particular, how does its stiffness or flexibility impact the experimental results?
The authors should take into account the material properties of the fabricated propeller identified through PIV analysis when comparing it with the CFD results.
The manuscript lacks sufficient detail regarding the numerical model employed. It is recommended that additional information be provided, such as whether a mesh (grid) independence test was conducted.
This document contains numerous grammatical errors, thus proofreading for grammar is required.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors have performed a detailed analysis of two drone rotors, one twisted and one untwisted. They have performed detailed experiments with phase-locked PIV and compared the experimental results with numerical results in terms of tip vortices and trailing edge vortices. The work was well presented, and I would recommend the publication of the manuscript with minor revisions.
1. In Certain places in the abstract, the authors are using active voice. This has to be changed to passive voice
2. It is known the authors are using a well-validated code. Still, to have proper continuity in this manuscript, it would be essential to detail of numerical model like turbulence model, first grid length near to the wall, y+, etc.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
interesting paper because it is a theme that concerns the sound emission of UAV blades.
Is it possible to evaluate the variations of the emissions in dB?
Is a frequency spectrum from 100 Hz to 10,000 Hz possible?
Is it possible to highlight in frequency what happens when the blades vary?
For acoustic measurements on UAVs you can see Ciaburro et al, Iannace et al; Papa et al
Author Response
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Author Response File: Author Response.pdf
