A Numerical Investigation of the Dynamic Interaction between the Deep-Sea Mining Vehicle and Sediment Plumes Based on a Small-Scale Analysis

Round 1

Reviewer 1 Report

The methodology is presented very clearly and comprehensively. The results and discussion are clearly described and supported by adequate visual presentation. 

The reviewed paper analyse dynamic interaction between the deep sea mining vehicle and sediment plumes on small scales. The flow field is discribed with a finite volume discretization. For the transient term BDF2 is used, the pressure velocity coupling equation was solved by the SIMPLE algorithm and the turbulence model RKE2L is applied for the continuous phase. To describe the case in which the individual particle dynamics affect the scaling solution in Euler field the Lagrangian discrete phase model was applied.
The manuscript is presented in a well structured manner. Results are based on the given methods. Data used in paper are well presented to readers. Also conclusions are clearly presented with ideas for improving future research.
Cited references are relevant.

I think that the paper is very well prepared and I have no special comments for improvement.

Author Response

The authors thank you for your recognition and look forward to your continued guidance on the further achievements.

Reviewer 2 Report

 Review reprt: A numerical investigation of dynamic interaction between the deep-sea mining vehicle and sediment plumes based on a small-scale analysis

 

Recommendation: Revise

             This article numerically investigates the interaction between a dredger and its plume. I think this article’s quality of numerical investigation is acceptable. However, its weaknesses such as its small-scale simulation (which is not applicable in reality), its validity in comparing with physical laboratory measurements, and the lack of reasons why the interaction between the ship and the plume is important make this article inappropriate to be published in its present form. Moreover, there are many typos, and many grammatical errors. I suggest the authors address my comments,

 

            Abstract

            - It is not clear why you need to investigate the interaction between a dredger and its plume.

- The last sentence of the abstract must indicate who will benefit from this research.

            

               Introduction

            - Ln 31, avoid bulk referencing without actually reviewing them.

            - The first paragraph of the introduction lacks sentences explaining why the sediment plume. I suggest moving Ln 47-58 to the first paragraph and smoothening them.         

            - Although I am happy with the Introduction, your literature review does not lead to your objective. Why do you want to quantify the dynamic interaction between the ship and the plume? What can you solve if you understand such interaction? I cannot find the reasons why you need to do what you did.

            - Ln 83-90, Why do you think your approach is better than the others?

            - Why cube? Why not cylindrical?

            - Ln 104, I do not see the Discussion in Section 4.

 

            Methods

            - please provide units of every parameter in Sec 2.1

            - Please add a list of acronyms containing all parameters and their units

            - Simulation cases are not realistic. Although you can produce beautiful figures for small-scale tests, they are not applicable to real dredgers. What is the benefit of your research if your result cannot be used in reality?

            - Ln 174, Why cube?

            - Ln 187, I cannot find a comparison between your model and your laboratory experiment. It is necessary to test the validity of your numerical simulation with real measurements.

            - Ln 196, what is O?

            - Ln 201, the current velocity was only 0.01 m/s? How much is the current speed in reality?

            - Table 1, why 0-15 cm? Ln 187, Did you apply the similarity rule for all parameters? If you applied the similitude, did you apply them to discharge rate, ship speed, and relative velocity in Table 5 too?

             

            Discussion

            - The Discussion is merged with the result. Nevertheless, I want the authors to discuss the applicability of their simulation on real-life dredgers. What kind of difficulty do you expect when applying this approach to a real situation? What weaknesses of your approach when you scale it up?

            - Who will benefit from your findings? Would your finding help solve anything?

            

Minor comments

            - Figures are too small. Letters in figures are not readable.

            - A lot of grammatical errors such as Ln 185,

   

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Author Response

The authors thank the reviewer for the careful reading and many constructive comments. This is beneficial to further improve the quality of the manuscript. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

I’ve read your manuscript with great interest. Deep-sea mining is our future, which is closer than many of us would imagine. So, you raise really good research questions about the vehicles of this mining and sediment plumes. Discussion of such technologies is really important internationally. Your research has allowed to answer successfully to the risen questions and to outline perspectives for further investigations. The methodology is reasonable and well-explained. The results are communicated appropriately. The paper is generally well-written and informative. Indeed, it should be strengthened in some aspects, but my general impression is really positive.

1)      Key words: please, avoid the words already used in the title.

2)      Introduction: please, add some information about the diversity of seafloor mineral resources and the economic efficiency of their extraction.

3)      Results (=your direct findings) and Discussion (=interpretations of your findings) should be different sections, as usually requested in high-class international journals.

4)      I think Discussion should consider the application of your findings to real environments. For instance, how different depth, different sedimentary particle size, different water salinity, etc. would affect the regularities, which you establish. I also feel that your outcomes allow to write a bit about the environmental effects of deep-sea mining (perturbation of sediments, weakening slopes, etc.).

5)      Conclusions: the practical importance of your research should be well explained in this section.

6)      The number of the cited sources can be enlarged (duplicated, at least).

7)      The writing is generally clear, but certain linguistic polishing is required.

The writing is generally clear, but certain linguistic polishing is required.

Author Response

The authors thank the reviewer for the careful reading. Many constructive comments have been provided to the authors for further research. Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Thank you. Although some comments were not satisfactorily responded, I am generally ok with the revision.