Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors present an analysis of the acoustic performance of heat exchangers based on triply periodic minimal surfaces (TPMS). The authors use a COMSOL (FEM) model, compared with experimental data to study how unit cell type, size, and volume fraction affect the sound transmission loss in water. On this work, I have the following comments:

• It can be assumed that these heat exchangers are typically placed in engine rooms in ships, where engine, pumps and other noisy systems operate. What is the interest to reduce the noise of the heat exchangers there? The motivations should be better discussed.
• The primary goal of heat exchangers is good thermal and hydraulic performance (high efficiency and low pressure losses). While acoustic performance could be interesting, how can the authors say that such TPMS structure could ultimately be adopted in real applications? Were such structures chosen based on previous thermo-hydraulic characterizations? If not, it would be hard to support their use only based on the acoustic performance.
• The FEM model is too succinctly discussed and lacks proper explanation to make it reproducible. For example, it lacks proper explanation of domains, equations, boundary conditions, mesh, pressure-structure coupling, adopted assumptions (e.g. are walls assumed to be rigid? Is the fluid stationary? Etc.)
• The instrumentation for the experimental data acquisition needs a better explanation (type, sensitivity, calibration, sampling rate, data acquisition system, amplifiers), and the uncertainties on the experimental results should also be discussed (number of repeated runs or averaging procedure, possible environmental factors, error bars on acquisitions, etc.).

In summary, my opinion is that the above aspects are currently limiting the validity of the proposed work, and need to be addressed before further consideration of this work.

Comments on the Quality of English Language

Minor revision of English language would be required

Author Response

Dear Reviewer,  

Thank you very much for your valuable comments. Your insights regarding the significance of reducing heat exchanger noise in the complex acoustic environment of a ship's engine room were particularly profound and constructive. We fully agree with your perspective and believe that further exploration of this aspect will greatly enhance the completeness and value of our study.  

In accordance with your suggestions, we have conducted in-depth deliberations and supplemented the discussion in the paper. Due to the substantial amount of additional content, figures have been included for better clarity. The revised section has been submitted as an attachment to the system for your review.  

With our highest regards.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors of the article present research on the sound characteristics in a shell-and-tube heat exchanger based on TPMS structures. Although the article is very interesting and quite well written, the purpose of the article is not clear to me. In their model and experimental studies, the authors artificially generate sound and analyse its dynamics in the heat exchanger. To my knowledge, the main factor causing noise inside a shell-and-tube heat exchanger comes from flowing fluids, but the authors do not refer in any way to the mechanism of noise generation during fluid movement. As the authors themselves write in the introduction, there are no systematic studies on noise and its characteristics in shell-and-tube heat exchangers. This is because the noise characteristics of a heat exchanger, excluding the sound characteristics of flowing fluids, do not have any practical application. The purpose of this research is not clear to me in any way, even though it is well described. Due to the application-oriented nature of the journal, I would like to ask you to address this issue. At this point, I am forced to rate the article as needing improvement with major revision.

Author Response

Dear Reviewer,  

         I have carefully reviewed the questions you raised regarding the manuscript. Your comments are indeed crucial, as research in the field of engineering applications should have clear practical significance—a point that was not explicitly articulated in the original text. In response, I have addressed your questions below and made corresponding revisions in the manuscript. Due to the substantial amount of content, I have included figures to provide a clearer explanation. The revised content has been submitted as an attachment to the system for your review.  

With my highest regards.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed my comments

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have provided strong justification for their position on sound transmission modelling in heat exchangers. Therefore, I am inclined to accept the article in its current form.