Hydrodynamic Structure with Scour Hole Downstream of Bed Sills
James Sutherland
Round 1
Reviewer 1 Report
This is a well-written paper that makes the most of the dataset collected. One minor point would be to check the consistency between upper case and lower case symbols.
This reviewer would have appreciated a little more detail on how to calculate the lengthscales.
My main concern about the paper is the final equation, where scour depth varies with sigma. What value are we to use for sigma? Under circumstances described in the paper, sigma = -5/3. Can we use this value in all circumstances? If we can always use -5/3, why not simplify the final equation? Both exponents could be reduced to values, rather than expressions. If we cannot assume that sigma = -5/3, how do we calculate it?
Also, it is worth noting that hc appears on both sides of the equation. And, for that matter, dc appears in both F_dc and lambda_c. Is this sensible? I am not arguing that this is incorrect, but that the inter-dependencies are not clear to the reader. Please give a bit more consideration to the presentation and interpretation of Equation 11. Also, would you suggest limits of applicability?
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
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Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
The manuscript presents a scaling approach obtained by applying the phenomenological theory of turbulence to predict the maximum equilibrium scour depth. The authors validated the proposed scaling approach by experimental data, and the results show a quite reasonable accuracy in predicting the equilibrium scour depth in different hydraulic structures. In general, the manuscript is well written, the structure and the presentation of the results as well as the discussion are clear. However, the novelty of the study is not well present, more clear and direct description of novelty should be provided. The conclusion is too long, and in most case, the authors are just repeating what they did in the text, therefore, the conclusion must be shorten and just give the real CONCLUSION from the study.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
The authors analyzed the hydrodynamics associated with the developed scour based on the experiment data and derived formula for prediction of the scour depth.
The authors should specify what time window (e.g. 1 minutes, 5 minutes) they used to calculate the time-averaged velocity U and W at Line 141. The authors also need to discuss the sensitivity of their results to the length of time window for averaging.
For figures 3-9, it would be better to replace vertical profiles with x-z coordinated contours of variables like U’ and W’. The contours help the audiences more easily and intuitively catch the magnitude and location of local maxima of variables.
Can the authors provide any explanation for no accumulation of sediment downstream of the scour hole?
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors exhaustively replied to reviewer's comments. The recommendation is: accept in present form.
