Numerical Study of Partial Dam–Break Flow with Arbitrary Dam Gate Location Using VOF Method

Round 1

Reviewer 1 Report

The background and introduction lists lots of papers but provides further details of very few of them. 

There is very little discussion of the LES modelling which must be improved. Discussion on mesh sizing is very limited.

• Are these hexahedral cells of uniform size throughout the domain?
• Is a mesh of 0.015m really appropriate for LES? Is this even an appropriate size for a RANS VOF calculation?
• Has there been refinement at walls to account for the boundary layer?
• Is there any refinement at the interface to capture behaviour in this zone? 

Images of the interface should be shown. When discussing Q criterion, iso-surfaces of this should also be shown through the domain to visualise the vortices.

 

Author Response

Please see the attachment file. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Please find attached my comments

Comments for author File: Comments.pdf

Author Response

REVIEWER 2

1. The abstract was added more detail
2. Some mistakes were modified
3. The introduction was added more information to make it clear.
4. Some references were rewritten.
5. Section 2 was developed much better.
6. Figure 2 was made more clearly.
7. I added the paper https://doi.org/10.1051/e3sconf/20160704004 to the reference list. The https://doi.org/10.1061/(ASCE)0733-9429(1999)125:7(696) was not suitable for my paper’s goal so we did not use it
8. Please kindly check on the manuscript to see all improvements.

Author Response File: Author Response.pdf

Reviewer 3 Report

In this work, the numerical tool FLOW-3D is utilized to simulate the Partial Dam-Break Flow by LES and VOF Method. The crucial influence of the width of dam gate and its position is evaluated. The research topic is interesting. The detailed comments are as follows.

1) The numerical scheme should be supplemented and discussed. I guess, perhaps, the first-order up-wind scheme is utilized for convection terms and the second order central scheme is used for diffusion term. Maybe, the explicit first order Euler is employed for the transient term. Moreover, the solution method for the NS equation in FLOW-3D should be outlined.

2) The boundary condition and the initial condition should be presented in this work which is important to reproduce this work. Additionally, there are many LES-based turbulence model. Please specify which LES model is used.

3) CFD is a powerful tool to analyze the fluid behavior and has been used in many engineering communities. It is suggested to make a brief discussion about the CFD engineering applications. Here are some examples which may be useful.

[1] Numerical investigation of particle motion at the steel—slag interface in continuous casting using VOF method and dynamic overset grids, Experimental and Computational Multiphase Flow, 2022

[2] Large eddy simulation of turbulent flow using the parallel computational fluid dynamics code GASFLOW-MPI, Nuclear Engineering and Technology, 2017.

[3] Inerting Strategy for a Demonstration-Scale Hot Cell Facility Based on Experiences from Pilot-Scale Argon Cell Facility Operation and CFD Analysis, Science and Technology of Nuclear Installations, 2021.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The corrections to the paper have made the methodology clearer.

The reasoning of the use of the chosen grid size is pragmatic, but not particularly scientific. It is not clear to the reader that decreasing the mesh size further would not influence the results. While I appreciate that it would be difficult to perform a parametric study at an increased resolution, performing one simulation to determine the discretisation error introduced would give more confidence in the results presented.

Author Response

Q: The reasoning for the use of the chosen grid size is pragmatic, but not particularly scientific. It is not clear to the reader that decreasing the mesh size further would not influence the results. While I appreciate that it would be difficult to perform a parametric study at an increased resolution, performing one simulation to determine the discretization error introduced would give more confidence in the results presented.

A: We added one more refinement grid size of 0.012 m to determine the discretization error by RMSE.  Considering the mesh quality and computational time, we decided 0.015 m is the optimal grid cell size. Please check on the manuscript for more detail.

Besides, many improvements were done to manuscript, including: modify Introduction, add some results of mesh sensitivity analysis, and make clear many discussions.

Thank you very much

Reviewer 2 Report

The figures still not very clear. It would be better if the authors could save the figures as vector graphs.

Author Response

Q. The figures still not very clear. It would be better if the authors could save the figures as vector graphs.

A. We modified it and other figures already.

Besides, many discussions were made clear, the Introduction was added in more detail. A new result of grid size was added to assess mesh sensitivity analysis carefully. Please check the manuscript for more detail.

 

Reviewer 3 Report

No further comments.

Author Response

The manuscript was developed and rewritten in many parts, including an introduction, result discussion. Besides, as suggested by a reviewer, a new refinement mesh was analyzed to evaluate mesh quality carefully.

Please kindly check on the manuscript for more detail

Thank you very much

Round 3

Reviewer 1 Report

Changes requested have been made

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

This is an interesting study, but in the opinion of this reviewer the paper should be rewritten and resubmitted after improving English language and style, following the structure of an academic article (according to the MDPI website) and discussing all the tables and figures. Here are some points:

• Poor English language proficiency… For example: Line 192: “There are 18 different case studies are implemented to…”. Also, Line 216-217: “One the other hand, after two seconds.” What does it mean? Please add a verb to this sentence.
• It is strongly suggested to the authors to follow an academic structure to write the manuscript. (https://www.mdpi.com/authors/layout#_bookmark8)
• This manuscript lacks the “Material and methods” section. Line 117-121 could be released in “Material and methods”.
• Line 35: “This method based on the assumption of disregarding...” As it is a fact, this sentence should be written in present tense.
• Line 36-39: “It investigated a variety of typical hydraulic…” It is suggested to rewrite this part in passive tense.
• Line 43: “Hien & Van” Don’t use this sign (&) please.
• Line 48-49: This sentence seems grammatically incorrect.
• Line 49-50: This sentence should be written in past tense.
• Line 53: “…have been rarely carried out in the former studies.” Please, add references.
• Line 81-82: Ambiguity! Please rewrite it.
• Line 107-109: Grammatically incorrect.
• Line 126-127: Lack of reference “range value of RMSE”
• Without enough explanation of domain and measurement points on reservoirs, the authors jumped to Fig 2 and 3, and compared some unknown data (which were not discussed). This part is vague, please rewrite it.
• Section 3.1.1 needs to be rewritten with more details.
• Line 153-162: As authors mentioned, this part contains restimulation of something which was done by reference [14]. What is the scientific gap that the authors fulfilled by restimulating?
• A lot of figures and tables were released in this manuscript without clear and comprehensive discussion. All figures need to be interpreted…As an emblem, Fig 5 (each graph) consists of three curves (Exp, 0.015 and 0.025 m). There is not any information and discussion available in the manuscript about them.
• Figure 19: Please superscript 3 in Q(m3/s).
• Line 305-306: “…by partial dam break flow of 18 cases indicated in Table 2…” Table 2 contains 9 cases!!! Please add the other ones to this table.
• Equation 5: Please discuss it more precisely. Is this equation extracted from the results of the current research? If not, please add the reference.

 

 

Author Response

Reviewer 1

This is an interesting study, but in the opinion of this reviewer the paper should be rewritten and resubmitted after improving English language and style, following the structure of an academic article (according to the MDPI website) and discussing all the tables and figures. Here are some points:

 

1. Poor English language proficiency… For example: Line 192: “There are 18 different case studies are implemented to…”. Also, Line 216-217: “One the other hand, after two seconds.” What does it mean? Please add a verb to this sentence.
2. I modified it. Please check in Manuscript

It is strongly suggested to the authors to follow an academic structure to write the manuscript. (https://www.mdpi.com/authors/layout#_bookmark8)

1. This manuscript lacks the “Material and methods” section. Line 117-121 could be released in “Material and methods”.
2. I added it. Please check in Manuscript
3. Line 35: “This method based on the assumption of disregarding...” As it is a fact, this sentence should be written in present tense.
4. I modified it. Please check in Manuscript
5. Line 36-39: “It investigated a variety of typical hydraulic…” It is suggested to rewrite this part in passive tense.
6. I modified it. Please check in Manuscript
7. Line 43: “Hien & Van” Don’t use this sign (&) please.
8. I modified it. Please check in Manuscript
9. Line 48-49: This sentence seems grammatically incorrect.
10. I modified it. Please check in Manuscript
11. Line 49-50: This sentence should be written in past tense.
12. I modified it. Please check in Manuscript

Line 53: “…have been rarely carried out in the former studies.” Please, add references.

1. I added it. Please check in Manuscript
2. Line 81-82: Ambiguity! Please rewrite it.
3. I modified it. Please check in Manuscript

 

Q.Line 107-109: Grammatically incorrect

. A. I modified it. Please check in Manuscript

Line 126-127: Lack of reference “range value of RMSE”

1. I added it. Please check in Manuscript
2. Without enough explanation of domain and measurement points on reservoirs, the authors jumped to Fig 2 and 3, and compared some unknown data (which were not discussed). This part is vague, please rewrite it.
3. I added it. Please check in Manuscript
4. Section 3.1.1 needs to be rewritten with more details.
5. I added it. Please check in Manuscript
6. Line 153-162: As authors mentioned, this part contains restimulation of something which was done by reference [14]. What is the scientific gap that the authors fulfilled by restimulating?

A lot of figures and tables were released in this manuscript without clear and comprehensive discussion. All figures need to be interpreted…As an emblem, Fig 5 (each graph) consists of three curves (Exp, 0.015 and 0.025 m). There is not any information and discussion available in the manuscript about them.

1. Figures 5 shows the very good matching between numerical results of water hydrograph yielded by fine mesh and observed data. While the underestimation and strong diffusion is observed in results obtained by coarser mesh. In comparison with Shi-gedaa’s solution obtained by 2D SWE, 3D revolution of shock wave in this study is much better [14]. Especially, at early stage of dam collapsed, 3D CFD method captured very well peak flow. This different between 3D and 2D solutions is that 3D CFD method account for turbulent phenomena in rapid flow while 2D SWEs does not.
2. Figure 19: Please superscript 3 in Q(m3/s).
3. I modified it. Please check in Manuscript
4. Line 305-306: “…by partial dam break flow of 18 cases indicated in Table 2…” Table 2 contains 9 cases!!! Please add the other ones to this table.
5. In fact, 9 cases A for symmetrical dam gate and 9 cases for asymmetrical one. So, there are18 cases in total.
6. Equation 5: Please discuss it more precisely. Is this equation extracted from the results of the current research? If not, please add the reference.
7. I added the reference. Please check in Manuscript

 

Author Response File: Author Response.docx

Reviewer 2 Report

In this paper, the authors investigated the dam gate break using the LES coupled with VOF method. The paper looks ok but I have a few comments for authors to address:

 

1, the reference of LES and VOF models are missing, especially for the LES model. There are several widely used LES models. Could the authors provide specific reasons for the selection of the models?

2, Any explanation on the outliers in figure 3? 

3, The quality of the plots can be improved by increasing the resolution and removing the gray borders.

4, The location of the figures can be further improved by putting them after the paragraphs discussing those figures. 

Author Response

Reviewer 2

In this paper, the authors investigated the dam gate break using the LES coupled with VOF method. The paper looks ok but I have a few comments for authors to address:

 

Q1, the reference of LES and VOF models are missing, especially for the LES model. There are several widely used LES models. Could the authors provide specific reasons for the selection of the models?

A1. LES model is more suitable than RANs one when applying to simulate dam break flow. This point was pointed out in Laroque (2013)

2, Any explanation on the outliers in figure 3? 

1. We admit I make some mistakes with these solutions so we did it again.

3, The quality of the plots can be improved by increasing the resolution and removing the gray borders.

1. I modified it. Please check in Manuscript

4, The location of the figures can be further improved by putting them after the paragraphs discussing those figures. 

1. I modified it. Please check in Manuscript

 

Author Response File: Author Response.docx

Reviewer 3 Report

1. Introduction can be improved. The authors can consider the following references:

https://doi.org/10.1140/epjp/i2019-12592-3

doi:10.5402/2011/809498

2. Governing equation section is incomplete, and must be completed including the following details:

-Discretization schemes of the governing equations

- Solution algorithm

-VOF model used in this research (Youngs, FCT, …)

-Turbulence model (Zero equation, …..)

3. Mesh size and time step independence are the main part of a numerical simulation. While, there is no information about them. Please explain more about mesh size and time step independence.

4. All parameters must be explained in Figure 1. For example, the parameter w was used for unequal lengths.

5. Some parameters including air entertainment was evaluated by the authors. Please explain the importance of this parameter in dam break.

6. The novelty of the paper must be explained more.

7. English language and style are fine/minor spell check required. For example, on page 3:

“The VOF is a surface-tracking technique, which are often used” must be corrected as “The VOF is a surface-tracking technique, which is often used”

Author Response

Reviewer 2

In this paper, the authors investigated the dam gate break using the LES coupled with VOF method. The paper looks ok but I have a few comments for authors to address:

 

Q1, the reference of LES and VOF models are missing, especially for the LES model. There are several widely used LES models. Could the authors provide specific reasons for the selection of the models?

A1. LES model is more suitable than RANs one when applying to simulate dam break flow. This point was pointed out in Laroque (2013)

2, Any explanation on the outliers in figure 3? 

1. We admit I make some mistakes with these solutions so we did it again.

3, The quality of the plots can be improved by increasing the resolution and removing the gray borders.

1. I modified it. Please check in Manuscript

4, The location of the figures can be further improved by putting them after the paragraphs discussing those figures. 

1. I modified it. Please check in Manuscript

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors have responded to each question/suggestion raised by this reviewer. I propose to accept the paper.

Reviewer 3 Report

In my opinion, the paper is acceptable in the present form.