Experimental Study on the Air Concentration Distribution of Aerated Jet Flows in a Plunge Pool
Round 1
Reviewer 1 Report
This article shows an interesting experimental campaign, aimed at characterizing the air concentration in water reservoirs when a jet impignes the water surface. The study is well motivated, and after addressing these comments I would recommend it for publication:
- Discuss in more detail what would be the impact of the inflow conditions on the results.
- The potential of using high-fidelity simulations could be discussed in the Introduction. For instance, Samanta et al. (J. Fluid Mech. 784, 681-693, 2015) have recently performed very highly resolved simulations with porosity, so progressively more complex phenomena can be efficiently simulated.
- Section 3: regarding the statement "It is reasonable to deduce that the initial jet velocity and the initial air concentration have little effect on axial air concentration attenuation in the free jet region", could the authors add a reference from the literature where this claim is supported? Or otherwise provide additional justification for it?
- The power-law relation to model the evolution of air concentration with distance from the nozzle, is it empirical? Can the authors discuss in a bit more detail why this functional form was chosen?
- Figure 3: the authors should provide the uncertainty of their measurements to further strengthen these results. In this context, the importance of accurate flow measurements in order to obtain adequate conclusions from a theoretical point of view was discussed by Vinuesa et al. (Exp. Fluids 55, 1751, 2014). This should be referred to in order to highlight the importance of adequate uncertainty quantification.
- Figure 5: is there any numerical database to compare these results with? Would it be possible to obtain better flow statistics, by maybe using ensemble averages of different flow realizations?
- Figure 6: What are the factors that produce so much deviation? In some points the deviations are of the order of 30%, this needs to be justified... is such a linear model correct? How could one incorporate more factors into the model description?
- Figure 7: redo and reorganize these figures so 1) there is not so much empty space in most of the panels and 2) all the panels of the same figure can be on the same page.
- In the conclusions the authors should add some comments on how the investigated cases are relevant to conditions encountered in nature and applications.
Author Response
Thank you for your constructive and helpful suggestion. The revised manuscript has undergone English language editing by MDPI to improve the clarity, fluency and readability.The itemized responses to the comments are listed in the attached Word document.
Author Response File: 
Author Response.docx
Reviewer 2 Report
A file with the suggestions is attached.
Comments for author File: 
Comments.pdf
Author Response
Thank you for your earnest review and helpful suggestion. The revised manuscript has undergone English language editing by MDPI to improve the clarity, fluency and readability.The itemized responses to the comments are listed in the attached Word document.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
That manuscript is now acceptable for publication.
Author Response
Dear Sir/Madam:
Thank you for your appreciation concerning our committed manuscript.
The amendments we made according to your constructive comments have improved the quality of our manuscript. Moreover, your suggestions can be beneficial and instructive for our further research.
Thanks again for your kind review and advice.
Yours faithfully,
Weilin Xu
Reviewer 2 Report
See attached file.
Comments for author File: Comments.pdf
Author Response
Dear Sir/Madam:
Thank you for your comments and advice concerning our committed manuscript.
All the comments and suggestions are constructive and helpful for the improvement of the manuscript as well as our further research. We have made several amendments correspondingly, which are highlighted in yellow in the revised version. Attached pleased find the point-by-point response to the reviewer’s comments. We hope that the revisions would meet with approval.
Thanks again for your kind review and comments.
Yours faithfully,
Weilin Xu
Author Response File: Author Response.docx
