A 3D BEM Model for the Hydrodynamic Analysis and Design of Heaving WEC Arrays Attached to a Breakwater

Round 1

Reviewer 1 Report

Major revision is suggested. Please see the attachment.

Comments for author File: Comments.pdf

Extensive editing of English language is required.

Author Response

Please see attached pdf-file.

Author Response File: Author Response.pdf

Reviewer 2 Report

General comments:

In this paper, a 3D hydrodynamic model based on Boundary Element Method is proposed, which considers the reflection effect of vertical wall and the hydrodynamic interaction between multiple bodies. The interaction of multiple WECs, nearshore topography, breakwater wall and PTO parameters are studied. Finally, a case study of a selected coastal site is carried out to demonstrate the feasibility and applicability of the model. The research can provide important reference for the development and planning of the WECs industry. However, there are still some minor problems that need to be solved in this paper. The manuscript may be recommended for publication if the following minor comments can be addressed:

 

Specific comments:

1. P2:31-57. The literature review is very limited and lacks relevant literatures in recent years. This should be strengthened. Otherwise, the value of the whole work appears to be low and more like a technical report. To ensure the completeness of the literature survey, the following references may be of interest to the authors and should be added to the manuscript:

[1]  Fully coupled analysis of an integrated floating wind-wave power generation platform in operational sea-states. Frontiers in Energy Research, 2022, 10:931057.

[2] Experimental and numerical investigation of WEC-type floating breakwaters: a single-pontoon oscillating buoy and a dual-pontoon oscillating water column. Coast Eng. 177, 104188.

[3] Experimental and numerical analysis of a hybrid WEC-breakwater system combining an oscillating water column and an oscillating buoy. Renew. Sustain. Energy Rev. 169, 112909.

 

2. P2:58-78. Research gap should be delivered on more clear way with directed necessity for the conducted research work in the introduction section. Please indicate how the author's method differs from that of other researchers and how novel it is.

 

3.P3: Equation (1). The mathematical equations in the article are not displayed clearly, please make a check.

 

4. The advantages of the 3D BEM model in evaluating the performance of WEC arrays are not expressed in the text. Can it provide comparative research content with other methods or provide more research results to demonstrate the innovation of this model in evaluating the performance of WEC arrays. Meanwhile, whether viscous correction is used for the multi-body hydrodynamic interaction problem? Some studies consider add additional viscosity on the gap fluid surface as done by the following research: A Coupled Hydrodynamic–Structural Model for Flexible Interconnected Multiple Floating Bodies, JMSE2023.

 

5. P8:327. It is mentioned that the case β =0° is also included for completeness, However, for the diffraction forces and Response Amplitude Operators below, there is no β=0° result. Do these contents need to be compared? Please explain the reason.

 

 

6. P11: Figure.11, The figure shows incomplete peak value of response of WEC in free-floating state, and the author did not analyze the figure. It seems that the response at the peak value is too large. Should the author consider adding viscous damping correction? Please supplement and improve.

 

7. P12:377-378, The Response Amplitude Operators under different BPTO and CPTO conditions are given above, but analysis and discussion are not conducted according to the corresponding results. Please add a paragraph of discussion and analysis. In order to understand the various responses for BPTO and CPTO.

 

8. P12:383, It is mentioned that the responses are very low if the WECs are centered on a node of the incident field, but the corresponding RAO comparison results under this conclusion are not given. Please add the corresponding results so that readers can understand this content.

Author Response

Please see attached pdf-file.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors established a 3D model of WEC arrays based on the Boundary Element Method and presented a case study of real example with long-term climatological data. The data of forces and responses on cylindrical WECs in different conditions have been organized to evaluate the performance of WEC arrays and the power output of the real case have been analyzed. The paper is appropriate for the journal. However, I believe a major revision is needed because of the following issues:

1. The literature review in the introduction section is insufficient and incomplete. More relevant studies on numerical model and physical model about WEC are needed for a better understanding of the research background and significance.

2. The authors failed to thoroughly elaborate the results, which is difficult for the readers to understand the conclusions. Fully elaborations for figures in sections 4 and 5 should be included.

3. The conclusions should be more well summarized and straightforward.

4. Grid independence analysis should be included.

5. The authors should further explain the reason why there is a bigger difference between the results of present model and the reference when ω is less than 1.5 in Figure 6 (b) and (c).

The language of the paper is not always appropriate. On many occasions, the authors did not use common and appropriate terminologies. I think native speakers or professional proofreaders are needed to address the language concerns of the manuscript.

Author Response

Please see attached pdf-file.

Author Response File: Author Response.pdf

Reviewer 4 Report

This is a well written article on “A 3D BEM model for the hydrodynamic analysis and design of 2 heaving WEC arrays attached to a breakwater”. I think it can be accepted after minor revision.

Comments and Suggestions

If possible, indicate the different parts of the article at the end of the introduction.

 

Do you have the copyright of the figure 1 and b?

Check the letter of all the equations

P4 L135.Check the equation 2

P4 L167.Check the equation 5C

P7 L269.Check the equation 10

P7 L284.Check the equation 13

P16 L479.Check the equation 17

P7 L265 Check the name of the figure 5

Please numerate the WECs in figure 4 and 5

How your method can be applied to optimization studies in order to maximize the power output of WEC?

How do reflective effects affect the PTO of the WECs, if it were a positive effect, how much would the PTO increase compared to the open sea?

Author Response

Please see attached pdf-file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The present version can be accepted.

Minor editing of English language is required.

Reviewer 3 Report

The authors addressed the majority of the criticisms and corrections. Paper can be accepted.

The quality of language has been improved.