Parametric Characterization and Multi-Objective Optimization of Low-Pressure Abrasive Water Jets for Biofouling Removal from Net Cages Using Response Surface Methodology and the Entropy Method

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, the authors systematically investigate the fouling-removal performance of a low-pressure abrasive water jet (LPAWJ). Numerical simulation, the Box–Behnken response surface method, and the entropy method are combined to evaluate the influence of key parameters and to develop an optimization model. Experiments on abrasive-jet net cleaning further validate the numerical predictions. The study is meaningful for advancing fouling-control technologies in marine aquaculture. Overall, the manuscript is clearly presented, but some issues should be addressed to improve its scientific rigor.

1: In the section “Particle trajectory calculation equation”, the force balance equation for a single abrasive particle would benefit from a clearer and more complete description. In particular, the manuscript should explicitly include the formulation of the additional (or added-mass) force term acting on the particle to improve the physical completeness of the model.

2: In the Introduction, the novelty and main contributions of the study could be stated more explicitly. A concise summary of how this work advances current research would help readers better appreciate its significance.

3: In Figure 7, the labels of the coordinate axes could be made more prominent. It is recommended to bold the axis labels to improve readability and consistency with the formatting of other figures.

4: The manuscript would be strengthened by adding a discussion of the study’s limitations and potential directions for future research in the conclusion section.

5: In the methodology and experimental sections, it may be helpful to provide additional details for reproducibility. For instance, including the MATLAB code used for data processing in an appendix or supplementary material would make the work more transparent and beneficial for future researchers.

Author Response

The response is provided in the Word file below.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The study addresses biofouling in deep-sea aquaculture cages and proposes using low-pressure abrasive water jets (LPAWJ) for cleaning. It combines CFD simulation (FLUENT), Box-Behnken design (RSM), and the entropy method to optimize three parameters: nozzle inlet pressure, outlet diameter, and target distance. Four indicators are weighted to compute an overall removal capability. The optimal parameters (4.5 MPa, 10 mm, 205.396 mm) improved removal capability by ~101% compared to the worst condition. Experimental validation confirmed the model’s predictions. The paper addresses a real-world problem in sustainable aquaculture with a promising cleaning technology. It combines CFD, RSM, and entropy weighting for multi-objective optimization, which is innovative. It also provides a well-structured approach to parameter selection and response modeling. The paper still needs revisions before acceptance by addressing the following issues:

1. Limited experiment scope: Only three operating conditions were tested experimentally, and cleaning was restricted to the central region of the net. This raises concerns about scalability and robustness. Authors should expand experiments or acquire experimental data from other researches to include more parameter combinations and full-net cleaning to validate real-world applicability.
2. Entropy method justification: While entropy weighting is objective, the paper does not compare it with other multi-criteria decision-making methods (e.g., AHP, TOPSIS). Please include a sensitivity analysis or comparison to confirm that entropy-based weights do not bias results.
3. ANOVA interpretation: The paper reports high R² values (0.9968), but does not address potential overfitting given the small number of experimental points. The paper must include residual plots or cross-validation to confirm model generalizability.
4. Experimental variability: Removal rates under optimized conditions (Condition 3) improved by ~100%, but the absolute removal rate (~32%) is still modest. Why does removal efficiency remain low? Whether could multiple passes or higher abrasive flow rates improve performance?
5. Environmental impact: The paper does not address the ecological implications of introducing quartz sand abrasives into marine environments.
6. Economic feasibility: No cost analysis is provided for implementing LPAWJ systems compared to conventional cleaning methods. It could be beneficial to add a brief discussion on operational costs and energy consumption.
7. Some figures (e.g., contour plots) lack clear captions and scale bars, making interpretation difficult. Please improve the figure qualities.
8. Language & Structure: While generally clear, some sections (e.g., governing equations) are overly detailed for the target audience. Authors may as well move lengthy derivations to an appendix and focus on key findings in the main text.

 

Comments on the Quality of English Language

The English is generally understandable, but it could be improved for clarity and conciseness. Some sentences are overly long and technical, which may hinder readability for a broader audience. Minor grammatical adjustments and simplification of complex phrases would enhance the overall flow. Additionally, figure captions and section transitions could be more descriptive to improve coherence.

Author Response

The response is provided in the Word file below.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript has been substantially strengthened and now demonstrates solid experimental support, rigorous model justification, and clearer presentation. The authors have satisfactorily addressed all major reviewer concerns. I believe the paper is suitable for publication after minor editorial polishing.

There are still a few small language errors throughout the manuscript. Examples include:

• “correonding author” → corresponding author
• A few long sentences in the Introduction and Methods could be simplified for readability.

 

Author Response

The response is provided in the Word file below.

Author Response File: Author Response.pdf