Extensive Discussions of the Eddy Dissipation Concept Constants and Numerical Simulations of the Sandia Flame D

Round 1

Reviewer 1 Report

Manuscript Number: Applsci-1849881-v1

 

Full Title: Extensive discussions of the Eddy Dissipation Concept constants and numerical simulations of the Sandia flame D

 

I – General Comments

The present manuscript deals with the effects of the secondary constant on the mean reaction rate, in which the limiting turbulence Reynolds number used for the validity of Eddy Dissipation Concept (EDC) is discussed. In general, the effects of the constants of the EDC model on the mean reaction rate are presented by using twenty combinations of the primary constants simulating a laboratory-scale turbulent jet flame, i.e., Sandia Flame D. The model comparison of flow and chemical kinetic mechanisms for methane-air combustion has been presented for Sandia Flame D by using Ansys Fluent. The Reynolds Stress Model (RSM) has been used for all the simulations. The manuscript is reasonable well organized and seems present contribution for the literature. I have some recommendations/questions addressed to the authors, before to accept their manuscript as Applied Science’s paper.

 

II - Specific Comments

(i) It is necessary to review the “Abstract”, preferably, no citing previous works. Put in other words, in “Abstract”, the main contribution of the present manuscript must be better clarified and the present state of the art concerning the investigated topic must also be introduced and contextualized.

(ii) The section “Introduction” must discuss/clarify the employed methodology to solve the proposed physical problem. The same section must also be finalized contextualizing the main contribution of the manuscript that justifies its publication in comparison with works already published. Why the manuscript does not cite previous works early published in Applied Sciences? Are there other publications about the research topic in Applied Sciences? That key point needs to be clarified by authors to justify their publication.

(iii) The manuscript must be numbered from page 1 until page 22. There is a numeration mistake starting page 10.  

(iv) On page 19, line 511, there is the following sentence: “It is expected to obtain better results using the advanced high-fidelity models, e.g., the full-spectrum k-distribution method [45-51] for radiation rather than the weighted sum of gray gas (WSGG) model [51] used in this work.”

Is it necessary to cite all references from [45] until [51]? An excessive citation including the first author “Wang, C. J.” has been identified.

(v) Equation (2) needs to be better introduced and interpreted.

(vi) In “section 3”, the physics about the transfer of mechanical energy from the mean flow to heat by turbulent effects is unclear. The authors should include additional comments aiming to clarify it.

(vii) A better explanation (physical sense) between Equations (27) and (31) is welcome to elucidate the use of Equation (32).     

(viii) The main conclusions from Table 1 can be organized and presented.

(ix) Please, increase the size of Figures 4-14. I had difficult with their subtitle.

(x) What was the uncertainty for the measured [23, 24] UU Reynolds normal stress profiles of Sandia Flame D?  What was the convergence criterion (mesh refinement details) for the used numerical results?

(xi) On page 19, line 519, there is the following comment: “There are some possible reasons for the deviations, including simplifications of the boundary settings, the turbulence, the turbulence-reaction interaction, and the radiation models.”

The authors should better detail all the mentioned reasons for the deviations. What is expected?

(xii) In my sincere opinion, there are lots of results to be understood and this has turned the reading a few tiring. In general, figures and tables should be better interpreted including physical sense in some test cases. I would like to recommend a suitable strategy to discuss the more relevant results. What are the more representative results and contributions? That is my main concern with the present manuscript. I hope that the authors can solve that situation in due time.

(xiii) In section 6, a perspective for future research is welcome.

 

III - Recommendation for the Applied Sciences´ Editor

In my opinion, the present manuscript needs attend all topics above presented. Upon consideration of all points above, I think the paper could be considered for publication in Applied Sciences.

Author Response

Thank you very much for your very useful comment. 

Author Response File: Author Response.docx

Reviewer 2 Report

 

The Eddy Dissipation Concept (EDC) has been thoroughly reviewed in this article. For this purpose, authors have simulated the Sundia flame D using the commercial code, ANSYS fluent. They have introduced their approach providing a brief literature review. I think the article is well written. I have the following concerns:

1)  The introduction is full of the values of few parameters; as a result, the article is difficult to follow. It brings the message that the underlying phenomena is dependent on certain particular values of a few parameters. Previous authors have also considered few values of the parameters. It is neither clear whether previously chosen values are inaccurate or not, and if so, what are the findings and suggested values. In other words, the novelty is not clear.

2) The methodology is not adequately presented so that the results can be re-produced. Section 5 jumps into ANSYS suddenly. It has been stated that the RSM is used for all simulations. So, what is RSM? How the use of RSM leads to what findings?

It these two points are satisfactorily addressed, then the article may turn into a publishable format.

 

 

 

 

Author Response

Thank you very much for your very useful comment. 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Manuscript Number: Applsci-1849881-V2

Full Title: Extensive discussions of the Eddy Dissipation Concept constants and numerical simulations of the Sandia flame D

 

The original text of the manuscript has been satisfactory revised. In my opinion, the manuscript can be published as an Applied Science’s paper.

Reviewer 2 Report

The revised version has addressed my concern to an acceptable level. My review is primarily in the context of turbulence and computational fluid dynamics. Readers in the field of combustion modeling may also find this paper useful.

The article is a single search story in which conclusions are supported by the data. My recommendation is to publish the article, and I also like to thank the authors for choosing such a difficult field of research and for choosing this journal so we can read their research findings.