An Experimental Investigation of Coherent Structures and Induced Noise Characteristics of the Partial Cavitating Flow on a Two-Dimensional Hydrofoil

Round 1

Reviewer 1 Report

In this paper, partial cavities including sheet and cloud cavities are explored experimentally on the 2D hydrofoil. The paper is very well-written, and I enjoyed reading this manuscript. I suggest publication of this work after minor revision.

-The authors should refer to more recent studies. For instance: In “The physical mechanism of the cavity inception is quite complex and somewhat different on scale models and full scale [2-4]”, recent studies on the deviation of the micro scale cavitation inception should be referred:

1. https://doi.org/10.1063/1.1827602
2. https://doi.org/10.1063/1.5051606
3. https://doi.org/10.1063/1.3671682
4. https://doi.org/10.1088/1361-6439/aab9d0

- How do you measure the freestream velocity? And why do you use freestream pressure in the cavitation number formula?

- It is mentioned that “For both small values of the angle of attack and the cavitation number, the cavity is short and thin so that the cavity and surrounding flow are stable. However, for large values of the incident angle and the cavitation number, the cavity is thick and long, and it becomes unstable.” However, we know that the lower cavitation number indicates severer cavitating flow. What do you mean by short and thin cavity for smaller values of cavitation number? Do you mean that collapse may happen earlier in lower cavitation number? Please explain this argument.

 

 

Author Response

We, all authors, appreciate your review. 

Response is enclosed.

Author Response File: Author Response.docx

Reviewer 2 Report

Cavitation is a complex multiphase flow that is of great research value due to its destructive capacity. This paper presents some experimental investigation on coherent structures and induced noise characteristics of partial cavitation on a two-dimensional hydrofoil for a series of cavitaton numbers. The results show that the hairpin vortices are dominant and robust feature of cloud cavitating flow. The research work and results of this paper are interesting. Some suggestions for revisions to improve the quality of the paper:

1. Studies related to propeller cavitation noise should be added to the research status. And the same to some numerical works.
2. What about acoustic absorption and reverberation of the test facility?
3. Figure 13 shows the location of the maximum amplitude for frequency domain is 0 Hz, why? Perhaps the average of the data should be taken when performing the Fourier transform.

Author Response

We, all authors, appreciate your review. 

Response is enclosed.

Author Response File: Author Response.docx