Experimental and Numerical Studies on the Efficacy of Water Mist to Suppress Hydrocarbon Fires in Enclosures

Round 1

Reviewer 1 Report

1. 1. The article adequately addresses the importance of fire protection in ship engine rooms, but it lacks a clear emphasis on the practical implications and real-world applications of the research. Readers may benefit from a more explicit connection between the study's findings and their potential impact on maritime safety.

2. 2. The critique of previous studies is comprehensive, particularly in highlighting the limited investigation of shielded fire scenarios and the infrequent measurement of heat release rate (HRR). However, the article could benefit from a more focused discussion on why these gaps matter in the context of ship safety and how addressing them could enhance current fire suppression strategies.

3. 3. While the article mentions the use of various computational fluid dynamics (CFD) modeling tools, it would be helpful to provide a comparative analysis of these tools' strengths and weaknesses in simulating fire scenarios. This could aid readers in understanding the reliability and applicability of different modeling approaches in the maritime context.

4. 4. The article touches upon the bans on Halon 1301 and the subsequent exploration of water mist spray as an alternative. However, it does not delve deeply into the environmental implications and regulatory considerations associated with these fire suppressants. Including a brief discussion on these aspects could enhance the article's completeness.

5. 5. The literature review successfully identifies research gaps and emphasizes the need for further investigations. However, it could be strengthened by proposing specific areas or methodologies for future research, providing readers with a clearer roadmap for advancing the field.

6. 6. The article could benefit from a more engaging and accessible writing style. While the technical details are crucial, presenting them in a more reader-friendly manner would make the content more appealing to a broader audience, including those without an extensive background in maritime engineering or fire safety.

Minor Editing is required.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The contents are under the scope of this journal. The main observations are listed below. The acceptance of the manuscript would depend on the major revision. The author needs to provide a point by point response or provide a rebuttal.

1. How did the experimental setup contribute to understanding the real-world efficacy of water mist in suppressing hydrocarbon fires in enclosures?

2. Revise the introduction such that each paragraph shall present the meaning of a concept/keyword. Each paragraph must present at least three theoretical reviews on the same concept/keyword. Also, the same paragraph should articulate at least three published results on the major concept/keyword. This would make the introduction suitable to announce the title, aim, objectives, and attract the interest of the readers. The introduction section can be supported with some more recent related literature especially since all references are not relatively recent. Introduction section can be supported with some more recent related literature like Corrosion Inhibitive Action of Tenofovir Disproxil Fumarate (TDF) for Low Carbon Steel in 1M HCl.

3. What specific hydrocarbon fuels were used in the experiments, and how did their characteristics impact the effectiveness of water mist suppression?

4. Can you elaborate on the numerical modeling techniques employed to simulate the behavior of hydrocarbon fires in enclosures and assess the efficacy of water mist as a suppressant?

5. Were there any notable differences between the experimental results and the outcomes predicted by numerical simulations? If so, how were these variations addressed or explained?

6. How did the researchers quantify the efficacy of water mist in terms of fire suppression, and what key performance indicators were used in both experimental and numerical studies?

7. Were there any challenges or limitations encountered during the experimental phase that could have influenced the interpretation of results or the generalizability of findings?

8. In the numerical studies, how were the boundary conditions and environmental factors considered to reflect real-world scenarios accurately?

9. Can you discuss any variations observed in the efficacy of water mist suppression concerning different enclosure sizes or geometries during both experimental and numerical investigations?

10. Were there specific design considerations or optimization strategies identified through the combined experimental and numerical studies to enhance the overall efficiency of water mist systems in hydrocarbon fire suppression?

11. How do the findings from this research contribute to the existing knowledge base on fire safety, and what potential applications or implications do they have for industrial or residential settings?

Minor editing of English language required

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

This work reviews the effectiveness of water mist in suppressing hydrocarbon fire in closed environments. It summarizes the conclusions of the experimental and numerical simulation studies. The following questions need to be considered carefully by the author:

(1) "For fires in closed environments, lesser amounts of water can extinguish larger fires compared to open spaces, due to the increased efficiency of vaporisation that can be attributed to heat confinement and the limited supply of oxygen in enclosures [10].", please expand on this sentence to help the reader understand better, i.e., how do the two parameters of "heat confinement" and "limited supply of oxygen" affect fire suppression in confined spaces?

(2) "Back et al. [21] reported that larger fires were easier and faster to extinguish than smaller fires due to the higher consumption of oxygen by the fire, and the increased generation of steam and turbulence created by the fire.", does this statement conflict with the conclusion of Figure 4? In the analysis, how to reflect the parameter of "oxygen concentration" in space, and the impact of this parameter on fire extinguishing time?

Author Response

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Reviewer 4 Report

This review report examines a total of 59 experimental and numerical analysis papers on water mist fire suppression and examines the effect of water mist on extinguishing hydrocarbon fires in enclosures.

The fire extinguishing mechanism for class A and class B fires in water mist was explained, and the test procedures and performance requirements for IMO maritime standards were examined.

In addition, authors looked at numerical modeling techniques, which are an alternative to full-scale experiments, and various previous research cases, and considered the sensitivity of numerical parameters for FDS.

This paper is expected to be helpful in conducting research on water mist fire suppression using numerical analysis.

Author Response

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Reviewer 5 Report

The authors highlight the numerical modelling of fire suppression using water mist, focusing on HRR, a key parameter to characterizing the growth and the suppression of fire. The manuscript is good, but not enough to have insights to identify a CFD model that can model fire extinguishment by water mist. Therefore, I propose to add some key figures to highlight the HRR effect of water mist. Additionally, Could you check whether the Q_dot (eq. a) is the fire size rather than heat release rate in page 15?

Author Response

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Author Response File: Author Response.docx