Flow Field Pattern and Hydrodynamic Characteristics of a Grid Device Made with Various Grid Bar Spacings at Different Inclination Angles

Round 1

Reviewer 1 Report

This study investigates the effects of inclination grid angles and grid bar spacing on hydrodynamic forces and flow field around a circular grid using CFD numerical simulation and flume tank experiments. This paper shows some interesting results from the numerical analysis, which has some practical importance in connection with fishing gear. However, in order to be accepted in the journal, minor revisions are required as listed below.

(1)   The results obtained in this study seems to be interesting from the view point of fluid mechanics, though, it is not clear at all how the results can be utilized for designing of fishing gear in practical applications. By elaborating from this view point in this paper, the importance of this study will be more emphasized.

(2)   P.5 Line No.207, “inner region of the boundary layer”: What kind of boundary layer flow are you dealing with in your model analysis?

(3)   According to Figure 1, d denotes the spacing of the grid, whereas in some places, d is defined to be the diameter of the grid bar.

(4)   Reference [22] on Page 5 just above Eqs. (4), (5) and (6) seems to be wrong citation. The paper is not related to turbulence modelling.

(5)   The wrong way of citing references: For example, on page 15 Line No. 91, written as Lsaksen [29], but it should be written as Lsaksen et al. [29], as there are three co-authors. On the same page’s Line No. 98, written Zhang Jian [15]. But write only the family name, probably Zhang. In addition, there are co-authors in this paper. Thus, it must be written as Zhang et al. [15]. Similar mistakes can be found in many places. This is a prerequisite for paper submission to an international journal!

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

I appreciate the dedication and thoroughness put into conducting this study. However, I regret to note that the research objectives should be better articulated as well as the presentation of the applied methodology (experimental and numerical) and the discussion of the results should be improved. Hence, the manuscript could be considered for publication on the JMSE after major revisions (detailed comments are presented in the attached file).  References included in the review are suggested for a reading from the authors to better place their study in the current scientific literature, not compulsory. Please cite selectively if you think it is useful.

 

Comments for author File: Comments.pdf

A very careful prood-reading is needed to improve the readability of the text.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 3 Report

Relevant and interesting article. But there are several issues which need to be addressed in my opinion. I invite the authors to revise the manuscript accordingly and/or rebute the following comments:

1. Abstract (32-34) seems a repetition of what was said immediately before.

2. There are many terms which are misplaced, not elegant, or not rigorous enough for a scientific paper, e.g. enhanced the vortex; dearth information; boasting a diameter; frame furnished; articulate the fluid's behaviour, sporting grid bar spacings, etc. Although one can follow what it is said, the text needs a review by a native speaker with knowledge in the field.

3. The CFD incoming flow field is homogeneous. Is the experimental one as well? How do we know?

4. a photo of the experimental setup and of the specimem need to be included for an experimental paper. Further information on the channel should be added.

5. the dimensions of the cfd domain (300D, 140D, ...) do not seem to comply with what I perceive from Figure 3 - they actually seem much smaller in the figure. Please clarify. What is the actual value of D.

6. A convergence test and / or proof of convergence of the CFD results is required.

7. Expressions (7) and (8) define quantities that do not seem to be used in the paper. Please show a sketch where it is clear what are these areas, what is the bar spacing, grid diameter, etc.

8. I do not understand how the circular grid diameter is 5mm in Table 1, for values of bar spacing much higher. 

9.  Most of the text in section 3.4 is a pure description of the plots. Therefore it should be reduced substantially. This is very clear in lines 359-370.

10. Same comment regarding Section 3.5: seems overly descriptive with little to no insight. Should be reduced considerably.

11. In the discussion:

11. a) lines 20-21: 1-29 seems like an introduction or abstract; not a discussion. Should be removed.

11. b) 26-27: The paper has not discussed hydrodynamic aspects related to efficiency of BRD. Why is it here in the discussion?

11. c) 32-37: this does not explain the physics, but only an intuitive somewhat lay-man comment. I am sure the authors will be able to provide some actual fluid dynamics insight here.

11 d) 31: the reduction of velocity deficit with bar spacing which is stated does not seem to happen when observing Figure 8. Then the bar spacing is shown as d, which is the diameter of the bars, which is not the same thing. Maybe I am not following the definition, which then points to comment no. 7.

11. e) 46: Figure 8 seems to contradict the authors. It seems to show that lower velocity reductions with lower angles.

11. f) 65-70: this is not really a discussion, but a set of obvious statements. Please remove.

11. g) 106: what does it mean to "enhance the flow velocity"? Maybe this is just a misplaced term?

11. h) 114-118: repeating.

11. i) From the previous points in 11., I believe that the discussion session should be greatly reduced and keep to what is actually shown in the paper.

See point 2 in the comments to authors (also replicated here):

2. There are many terms which are misplaced, not elegant, or not rigorous for a scientific paper, e.g.:

enhanced the vortex; dearth information; boasting a diameter; frame furnished; articulate the fluid's behaviour, sporting grid bar spacings, etc. Although one can infer the meaning of what it is said, the text definetely needs a review by a native speaker with knowledge in the field.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I confirmed that the authors made revisions properly in response to the reviewer's comments. Thus the paper can be published now.

Author Response

Thank you very much for your professional suggestions. Our article can be improved largely because of your valuable suggestions.

Reviewer 2 Report

The Authors have addressed most of my comments. Dimensionless plots are still advised. I still believe that a detailed discussion of the effect of the simulated flow field on fish behavior would improve the value of the study.

At the end, the revised manuscript could be considered for publication after minor revisions.

A careful proof-reading is still needed to improve English language.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors have successfully addressed all of this reviewer's comments.

Still some ill terms. Nothing major, though.

Author Response

Thank you for your comment concerning our manuscript. Your comment is very valuable and helpful for improving our paper. We have studied comments carefully and polished the manuscript. We hope it meets with approval.