A Design-Oriented Model for Transmission Loss Optimization in Marine DOCs

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,
The article concerns chemical and acoustic emissions from marine combustion engine, so the topic is actual, and problem raised is accurate. According to the referenced literature, which is sufficient and relevant to the topic, the problem raised in the article is novel. Conclusion correspond with research results.
My overall opinion on the manuscript is positive, however there are some issues that must be corrected/improved:
- Authors do not set the problem in a specific surrounding - we know nothing about the boat/ship, and especially the engine. Authors should provide detailed data of the engine, including brake specific fuel consumption characterisic and choose the point which is analysed. We only know boundary conditions from Table 2. But do they refer to nominal working point? How inlet speed of 44 m/s was determined/measured?
- In Table 1 parameters are in italics, whereas in Table 3 parameters are normal font.
- In Figure 6 - dimension lines require arrows. Moreover, the quality of this Figure, and Figure 4 should be improved.
- There is an editorial error - the power of 3 should be written as superscript.

Sincerely,
Reviewer 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors This manuscript presents a computational framework based on a CFD-FEM simulation approach to model and optimise the acoustic characteristics of marine EGCS, aiming to provide a better solution for reducing exhaust noise. However, it should be revised and improved for considering its publication. Main suggestions are the following:   1 Figures 1, 3 and 4 need to be clearer.2.To improve the layout of figure.   2 It is recommended that the four figures be distributed in a square.   3 Align the top and bottom of figures 6 and 9 with the centre axis.   4 Add to the paper about the process of setting experimental parameters for honeycomb monomers in DOC.   5 Illustration of the availability of CFD-FEM data based on the comparison of CFD-FEM data with experimental data in Figure 5.   6 What are the advantages of using the integral area of the TL curve as an optimisation objective over using the peaks and valleys of the TL curve as an optimisation objective, and is there a problem of the maximum value being too different from the minimum value.   7 Can the effect of each parameter on the TL curve be visualized.   8 Inclusion of the volume calculation process for the optimised model.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The study presents the CFD-FEA optimisation of the acoustic properties of Exhaust Gas Cleaning Systems, considering NOx and SOx limits. While the work represents a valuable contribution to the field, the following comments should be addressed prior to acceptance for publication:

1. The introduction needs to be enhanced.

2. Clearly highlight the novelty of the proposed study.

3. Provide detailed information regarding the computational grid.

4. How do you ensure that the results are mesh-independent? A proper mesh sensitivity study is essential since CFD and FEM tools are utilized.

5. Explain the influence of the computational mesh on the velocity field obtained.

6. The authors state: "Figure 5 reports the comparison between numerical and experimental TL, highlighting a good correlation." How is "good correlation" defined? Provide error metrics and elaborate further on where the deviations between experimental and simulated values are attributed.

7. Include a section with a reflective discussion of the findings. What are the implications and impacts on the industry? Are the results scalable to different sizes? Additionally, discuss the limitations of the study.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I am satisfied with the modifications the authors have made.