Evaluation of Three-Dimensional Environmental Hydraulic Modeling in Scour Hole

Round 1

Reviewer 1 Report

I reject this article, because the article is self-plagiarism of Reference 7.

Author Response

Thank you for your comment.

The reviewer can feel that our present manuscript share several things in common with reference 7, which is our previous published paper.

Actually the results of two papers are coming from our same project, but we separate the topics:

- the last paper was focusing comparing the turbulent schemes of OpenFOAM model to find the best turbulent solution for modeling the flow in scour hole,

- This present manuscript is about comparing the performance of two different popular models, which are widely used, in order to give a hint on choosing the right one for other similar simulation.

 

Since we want to focus on the most important property of scour hole, that is turbulence, so we analyze the velocity and turbulent kinetic energy in both papers, then the approaching is quite similar, however the details in comparison and purposes are different for them.

 

Also, we used different laboratory experiment cases for the two papers in purpose.

 

So, our intension is basically different for reference 7 and this manuscript. We also tried our best to re-write the content to avoid the self-plagiarism.

 

We appreciate the comment from the reviewer, but we hope the reviewer can take a little more time to read our manuscript.

Thank you.

Reviewer 2 Report

Some obvious edits include (line number given in [ ]):

[50] inadvertent line break

[61] need to be careful, flow around a sedan (compressible flow) is different than water flow around/over a rigid boundary (essentially incompressible flow)

[66-68] “there is not many works focusing on the flow near the wall, such as flow in scour hole according to authors’ knowledge.”  The authors should acknowledge references 7, 8, and 11 here as they acknowledge this work later (lines 126, 259) when choosing a turbulence scheme.  They can’t have it both ways, i.e., imply very little research has been conducted on this topic and proceed to quote from the considerable body of literature that exists.  There is plenty of literature regarding flow near a boundary, but arguably less on coupled flow over a mobile bed.

[85] “the” in front of compare should be deleted

[176] second instance of “for” should be deleted

[245] “compares” should be “compared”

 

The paper does not explicitly state if the models are used in coupled mode – fluid-sediment interaction.  Does the fluid move the sediment in the numerical models and yield a scour hole?  Or was the profile of the laboratory observed scour hole coded into the boundary mesh of the models?

Nor does the paper explicitly indicate that the scour hole results at the transition of a rigid bottom to a mobile bed; for example, what might occur downstream of an apron used beneath a hydraulic jump.

The scour hole that forms around a bridge pier (a vertical member piercing the water surface and riverbed is quite different from that which forms at the transition from a rigid bottom to a mobile bed.  The reference to “bridge pier” in line 34 should be removed.

I have significant experience with physical hydraulic modelling involving mobile beds and I have never known a laboratory model to take 12 days to reach equilibrium.  That it took 12 days to reach equilibrium is very odd.

This paper doesn't contain many references.  There have been countless conferences on numerical modelling that have looked at the ability of various models to reproduce either prototype or model scale data.  Of the 11 references, 3 are by Nguyen or Park.

Author Response

Thank you very much for your valuable recommendation and comments. We revised the paper considering reviewers' comments and recommendations very carefully. All the reply on the comments are in the attached file. We hope that the revised paper may satisfy the requirements from the journal. 

Author Response File: Author Response.docx

Reviewer 3 Report

Please see the attached file

Comments for author File: Comments.pdf

Author Response

Thank you very much for your valuable recommendation and comments. We revised the paper considering reviewers' comments and recommendations very carefully. all the reply on the comments are in the attached file. We hope that the revised paper may satisfy the requirements from the journal. 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I agree to the publication of this paper.

Reviewer 3 Report

Authors revised the paper as per my previous remarks and it improved the paper a lot. 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The article just compared two numerical modeling in flow turbulence within a scour hole. I can hardly find novelty in this study. There is neither improvement in model codes nor solution to any scientific problem in turbulence with a scour hole. The conclusion is also useless since the authors found two models can not well simulate the turbulent flow. 

Reviewer 2 Report

The choice of topic, i.e., investigating the accuracy of different 3D numerical models in scour holes, is essential and fits the journal's scope. However, the scientific sound of the manuscript is very low. Therefore I reject it in its present form

Introduction and problem statement: the motivations are unclear. The comparison of the two models does not certainly constitute scientific value. Why is this comparison necessary? I find it a significant shortcoming that the topic (examining the accuracy of 3D models) is barely presented. However, several studies have already addressed this topic. What are these studies (e.g. Torok et al., 2007: doi.org/10.3390/w9010056)? What are the main achievements and shortcomings? Based on such a thorough introduction, a clear motivation must be formulated: what question are they looking for to answer?

Methodology: 
Very concise. Perhaps after a clear problem statement, it would emerge which property/part of the models should be emphasized (e.g., turbulent kinetic energy or shear stress calculation method) and presented in more detail. Laboratory measurements are also presented very briefly. I hardly found a reference to the measurements.

Conclusion:
I can only repeat myself: since there is no clear motivation or objective, the conclusion is very general and not very scientific.

My opinion is that the topic under study is valuable, and the authors’ work has great potential.
I recommend re-submitting the manuscript after a revision.

 

Reviewer 3 Report

This paper mainly studies the performance of an open source code OpenFOAM and a commercial software Ansys Fluent in simulating the turbulent flow through a scour holes developed in sand bed channel.  The authors only compared the calculation results of the two CFD software without doing any innovative work. It looks more like a homework. Therefore, I reject this manuscript.