Formulation of a Jet Fuel Surrogate and Its Kinetic Chemical Mechanism by Emulating Physical and Chemical Properties of Real Jet Fuel

Round 1

Reviewer 1 Report

This paper developed a new four-component jet fuel surrogate (n-dodecane/iso-octane/iso-547 cetane/decalin/toluene) by formulating with a property optimizer. A reduced and robust kinetic chemical mechanism (containing 124 species and 590 reactions) that could be directly employed in practical engine combustion simulations is also developed for the presented surrogate. The mechanism is validated by comprehensive experimental data including ignition delay time (IDT) determined in shock tube and rapid compression machine (RCM), species mole fractions measured in premixed flames and jet stirred reactor (JSR), and laminar flame speeds. The comparison results between the predictions and measurements indicated that the current kinetic mechanism is capable of reflecting the oxidation process of real jet fuel and could be applied in practical engine computational fluid dynamic (CFD) simulation. All my concerns are list below:

(1)   The innovation of this paper is not well displayed, it’s better to list the contributions one by one. In addition, the research results are limited to the validation of each component and the surrogate fuel mixture, and do not involve the quantitatively analysis of the agreement between calculated values by surrogate and measured data of target jet fuel.

(2)   This paper is not well organized, which can make readers confused. Only a brief description of the related results of different researchers is given in the introduction and none of them analyze nor clarify the related problems in the study of the development of jet fuel surrogates and their corresponding kinetic mechanisms.

(3)   It is recommended that quantitatively analysis of the agreement between calculated values by surrogate and measured data of target jet fuel should be presented in detail. Meanwhile, the physical surrogate model is necessary to validate the performance of the surrogate jet fuel under practical conditions.

(4)   Other details: the choices of the LHV of JP-8 fuel and surface tension of Jet-A used as the references are lack of theorical basis; the format of Table 4 is not standardized.

Minor editing of English language required

Author Response

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Reviewer 2 Report

The article named: "A new-formulated surrogate jet fuel and its chemical kinetics is focussed on the determination of the suitable composition of mixture with similarity fuel properties as jet fuel. The main properties as CN, TSI, MW, LHV, H/C,  were determined and compared with jet fuel. The mechanism was validated by IDT, RCM, JSR and lamilar flame speed for different equivalent ration. The predicted model has good corelation with meassuring data. However, the kinetic model is not deaply descriebed. It was not desriebed the methods of research, as determination of gasses concentration by ignation formed. In the based evaluation, I suggest minor revision. 

The main disadvantedge is, that the metodology of determination products, which are described in chemical kinetics model are not descriebed. The manuscript presented the a lot of the reactions, which could help to described of new model, however, the model is not confirmed by analytics results. The authors should discriebed, how the products were determinated. Therefore, the conclusions are not confirmed by analytics results, therefore the article can not be published before added the methodology of determination. The tables and figures are good descriebed and they help to uderstanding of the results.

Author Response

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Reviewer 3 Report

 

•                 Title and Abstract- I suggest revising the title. The authors have mentioned various keywords it should be more precise. The keyword multiple times used can be modified.

•                 Abstract need be enhanced it has to address briefly and describe the aim, objective, and important findings accordingly. 

•                 Introduction lacks clarity and reduce the page and word count for the introduction. Rather detailed explanation a  comparison table can be included. 

•                 The research gap and need to review study the article in the present scenario is not justified strongly 

•                 A clear flow chart of the work/process  need to be included in the materials and methods section and reduce the figure count 

•                 Real-time images of the engine need to be included in place of figure, image quality need to be included. 

•                 The authors have more manuscript on the similar work, justify how it is not similar to the previous works of the authors.

·                  More quantitative and qualitative analysis is required 10.1016/j.jclepro.2021.129495,10.1016/j.jclepro.2023.137298,

•                 Conclusion Section is too weak for a research article.

Minor improvement

Author Response

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Reviewer 4 Report

Title: A new-formulated surrogate jet fuel and its chemical kinetic mechanism

Manuscript ID: sustainability-2520795

Authors: Li et al.

 

Dear Authors,

 

Thank you for the opportunity to read your article. I found the topic is interesting and fundamental. Generally speaking, there are some results presented in order to capture some trends but the methods and results need more clear explanation and detail discussion with fair point of view. I suggest that this article will be revised extensively before its re-submission for another review process if applicable. As a conclusion, I recommend its major revision at this state.

 

I hope my comments are helpful.

Good luck,

A reviewer

 

Major concerns:

“Abstract”

-Please consider briefly mentioning background of the study by following the author guideline.

“Abstract: The abstract should be a total of about 200 words maximum. The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used; 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.”

https://www.mdpi.com/journal/sustainability/instructions

 

“Keywords”

->Please consider providing keywords that are not used in the article title.

 

“1. Introduction”

-In the introduction, please consider describing the unique contribution of your study over literature.

 

“2. Formulation of jet fuel surrogate”

“2.1 Target fuel and its properties”

-Lines 112-113: “…due to the absence of the experimental data…surface tension of…were used…”->In this statement, please consider justification of this replacement.

 

“2.2 Formation of jet fuel surrogate”

-Table 3 (and elsewhere): please consider defining all the symbols used in equations.

-“Grunberg-Nissan equation”->Please provide a reference of the equation.

 

“3. Kinetic modelling”

-In this section, please consider mentioning the unique contribution of this study in terms of methodology.

 

“4. Discussion”->4. Results and discussion?

-In general, please consider (a) describing and discussing the results more in detail, and (b) providing justification of all the important parameters you selected and used for your study.

 

“4.1. Verifications of toluene”

-Fig.4: Please describe the results more in detail, for example, the effect of Toluene volume, temperature, pressure (?) as well as the models.

 

“4.1.2 Species concentration”

-Fig.6 (and elsewhere): In the figure title, please consider stating all the important parameters (e.g., pressure 10 atm) you used to generate the data plotted in the figure.

 

“4.1.3. Laminar flame speed”

-Lines 339-340: “…P=1 atm…P=3 atm…”->Please consider justifying the conditions you selected since in line 304 you selected 10 atm that is quite different from those selected to generate Fig.8.

 

Minor concerns:

-Please consider polishing English more. You may use some of my comments above for this purpose.

Moderate editing of English language required

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

After the re-review, it can be enunciated that the authors thoroughly elaborated all the reviewer's requests and comments. The article was improved the innovation description of this paper and was amended the description of related problems in the study of the development of jet fuel surrogates and their corresponding kinetic mechanisms in the introduction. Furthermore, the quantitatively analysis of the agreement between calculated values by surrogate and measured data of target jet fuel in the current study has been modified to clarify the research significance of this paper. As a result, the article has been properly revised and can be published.

Able to read properly.

Reviewer 4 Report

Dear Authors,

As all the comments were addressed, I would suggest the journal accept this article for its publication.

Best regards,
A reviewer

Minor editing of English language required