Numerical Investigation of Sloshing in Rectangular Tank with Permeable Baffle

Round 1

Reviewer 1 Report

better describing used models

explain BEM

better describing permeable baffle

 

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

The two-dimensional sloshing in a rectangular tanks with a baffle/screen in the middle is normally treated as a benchmark problem. It is usually considered in textbooks (yes, see, [29]) to demonstrate why and how this kind of internal structures may damp the violent resonant sloshing.

I did not find any physical findings in the manuscript. Properly, numerical examples (simulations) are the only its results. And I do not see something new and interesting in the CFD codes; these are standard.

However, the manuscript can be published, after an appropriate revision, because the aforementioned simulations may be useful for other researchers working on analogous CFD solvers. At least, for verification of their codes. 

The revisions suggest the following major changes:

1) The authors use standard codes. I do not see a novelty in the codes, which is proposed by the authors. From this point of view, something should be done with section 2. It misses the boundary conditions on the free surface and wetted structures (tank walls). It looks like the author have reprinted the governing equations from the codes manual. The simplest way is just to exclude this section but refer to the manual. An alternative is to make the free-surface problem complete adding and explaining all the governing equations and boundary conditions. 

2) When it comes to (8)-(11), I give up finding how (11) affects the undamped solution (8)-(10). Again, it looks like the authors do not understand the theoretical sloshing. The linear damping (here, (11) expresses the logarithmic decrement) must affect (8)! Please, read, for instance, chapter 6 in [29] and correct/exclude (8)-(11). 

3) Natural sloshing frequencies of the baffled sloshing. These were considered as a very particular case in [A]. Please, do compare with your results. 

4) Figure 5 demonstrates higher Fourier harmonics, which are normally a consequence of the secondary resonance for shallow water. Please, discuss this point. [31] and chapter 8 in [29] have an appropriate material for this discussion. Please, also note that internal structures may cause more secondary resonances [B] in the hydrodynamic system.

5) Chapter 6 in [29] shows that flow separation at the baffle edge causes the nonlinear (quadratic) damping law. How is it accounted in the mathematical/numerical model? Please, clarify. 

 

[A] Faltinsen OM., Timokha AN (2011) Natural sloshing frequencies and modes in a rectangular tank with a slat-type screen. J. Sound Vibr., 330, 1490-1503. 

[B] Faltinsen OM., Firoozkoohi R., Timokha AN (2011) Effect of central slotted screen with a high solidity ratio on the secondary resonance phenomenon for liquid sloshing in a rectangular tank. Physics of Fluids, 23, Issue 6, Art. 062106. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I am happy with changes. The manuscript can be accepted.