Time–Frequency Analysis of Nonlinear Dynamics of an Aquaculture Cage Array in Waves

Round 1

Reviewer 1 Report

The paper has significant shortcomings in the used methodology:

- In Chapter 2.2.2 presented Eqs. (6) and (7) are used for modelling rigid body motions, so they cannot be used for „ the elastic deformation of the floating collar“ as indicated in the chapter.

- In Chapter 2.2.2, it is written, „Therefore, the dynamic response of the aquaculture cage array is examined under the lumped mass framework in the frequency domain.“. The frequency domain approach assumes that the observed system is linear, i.e. the displacements of an observed structure are assumed small. This assumption cannot be used for aquaculture cages. For example, the net certainly has large displacements. Moreover, the mathematical models used for calculating the motions of the net and mooring lines are non-linear and cannot be adequately linearised to be a part of the frequency domain calculations.

- In Chapter 2.2.2, it is written, „For the second-order LF response, it is necessary to obtain from the force cross-spectra matrix.“. In the usual potential theory, the LF response (caused by second-order wave forces), assumes small displacements of the system, which is inadequate for aquaculture cages.

 

Author Response

We thanks the reviewer for the time and effort. The detailed response can be found attached.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript jmse-2590880 - "Time-frequency analysis on nonlinear dynamics of an aquaculture cage array in waves" provides an up-to-date and important information on the nonlinear dynamics of an aquaculture cage array via time-frequency analysis. This data is relevant for a broad public since future fish floating cage aquaculture can be potentially designed to withstand severe conditions in the open oceans.

The subject addressed in this article is worthy of investigation and is appropriate for the journal. The information presented is new and conclusions are supported by the data. Organization of the manuscript as well as figures and tables are appropriate.

The background provides sufficient literature, the methodology is sound, results are explanatory and well-discussed. Overall, a good read.

My overall recommendation for this paper is to be published in Journal of Marine Science and Engineering following a minor revision.

-        In the manuscript ”Zhu Liu1, Yuan Cheng 2, Jinfang Wang 1, Hongyu Zhu 2, Zhijing Xu 2 and *” should be replaced with ” Liu Zhu , Yuan Cheng , Jinfang Wang, Hongyu Zhu and Zhijing Xu *”

-        Minor editing of English language required.

Author Response

We thank the reviewer for the time and effort, the detailed response can be found attached.

Author Response File: Author Response.docx

Reviewer 3 Report

Please see the attachment.

Comments for author File: Comments.pdf

Moderate editing of English language is required.

Author Response

We thank the reviewer for the time and effort, the detailed response can be found attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thank you for the answers. As indicated in the title, abstract and introduction, the paper aims to study the nonlinear dynamics of an aquaculture cage array. The presented methodology is inappropriate for this purpose. Consequently, the main findings and conclusions are not adequately supported and cannot considered as valid.

 

Reviewer 3 Report

The present version can be accepted.

Minor editing of English language is required.