Numerical Study of Flow Downstream a Step with a Cylinder Part 1: Validation of the Numerical Simulations
Round 1
Reviewer 1 Report
The authors presented a Numerical study of Flow Downstream a Step with a Cylinder.
The first part of the work was dedicated to the validation of the numerical models and the results are presented in Part 2.
The authors must explain why the work is divided to 2 parts. Is it necessary to present the validation in a separate paper ?
For Part 1:
The main findings are to be mentioned in the abstract.
The introduction is relatively short and should be extended.
The governing equations and boundary conditions are to be presented before the mesh generation.
Why the buoyancy forces exist in the laminar formulation and doesn’t exist in turbulent formulation.
How the buoyancy terms are treated ? have you considered the Boussinesq approximation ? to be explained.
How the pressure terms are treated ?
More details on the numerical methods are to be provided.
What is the convergence criterion?
The authors considered time depending governing equations, thus the time at which the results are presented is to be indicated.
A 2D validation/verification (2D flow structure for example) is to be added.
Avoid the green background used in some figures
How can you explain the notable differences in Fig 11?
For Part 2:
some quantitative results are to be added to the abstract.
The introduction is to be extended.
The novelty of the work is to be clearly stated.
The used turbulence model is to be justified
A figure presenting the used mesh is to be added
A grid sensitivity test is to be performed.
Arrows are to be added on the streamlines for a better understanding of the flow’s directions (Figs 6 and 9).
The legend of fig 13, is very small.
Why the results are not limited to the more accurate models, found in part 1?
Author Response
First of all, the authors would like to thank the reviewers for the useful comments and believe that they provided the opportunity to improve the quality of the work. Every attempt has been made to address and incorporate the comments accordingly. The following is intended to provide itemized responses to the comments.
With kind regards
Author Response File: 
Author Response.docx
Reviewer 2 Report
Please see the attachment
Comments for author File: 
Comments.pdf
Author Response
First of all, the authors would like to thank the reviewers for the useful comments and believe that they provided the opportunity to improve the quality of the work. Every attempt has been made to address and incorporate the comments accordingly. The following is intended to provide itemized responses to the comments.
With kind regards
Author Response File: Author Response.docx
Reviewer 3 Report
The work done is OK although I do not see much novelty in this work. However, I suggest the following :
Why you do not use the simplified form for NS equations?
Line162: mean courant number or max courant number?
Explain better how you created Figure 6 and 7.
Figure 9 Why you include data for Reynolds higher that 9 000 if this study ends in that regime.
Author Response
First of all, the authors would like to thank the reviewers for the useful comments and believe that they provided the opportunity to improve the quality of the work. Every attempt has been made to address and incorporate the comments accordingly. The following is intended to provide itemized responses to the comments.
With kind regards
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Accept as it is
