Residue Cost Formation of a High Bypass Turbofan Engine

Round 1

Reviewer 1 Report

The authors examine the performance of a turbofan engine, by exploiting an exergetic analysis method. At the present study the exergetic analysis is coupled with an engine performance assessment model that dictates the effect of low component efficiency at the overall engine performance. Τhe aforementioned thermodynamic model is combined with an engine operating cost analysis that correlates the low component efficiency and pollutants formation with the increase of fuel consumption. The present research considers the GE90-115B high-bypass turbofan engine under takeoff conditions, as a case study. The concept is interesting and clearly presented, as is the motivation of the work and the research interest. I consider the manuscript fit for journal publication, provided that a few minor remarks are addressed.

- Literature review & research design: solid. All the assumptions made during the study are thoroughly explained by references and no major unwarrantable hypotheses were made. A more detailed explanation about the working media properties is kindly requested, as the ideal gas assumption for the whole engine may affect the accuracy of performance simulations. The theoretical background of the paper is strong the study does not lack justification in any of the key areas.

- Results: the study completely covers all the key areas of the exergetic performance analysis, as well as its correlation with the total operating cost of the engine. Additionally, the research is thorough, as a large number of correlations have been extracted, and great attention to detail was given in order to depict the results in a comprehensive manner.

- English, figures, tables: the figures could be significantly improved in terms of aesthetics and readability. Moreover, the tables used at the manuscript can be revised to be more comprehensive by the reader. Concerning the use of English language, though, I suggest that the whole manuscript undergoes a grammar and syntax revision, preferably by a native English speaker. This will significantly improve the quality of the, strong-allround, manuscript.

Author Response

To Reviewer 1

We would like to thank the reviewer #1  for his valuable comments to improve our manuscript entitled: Residues cost formation of a high bypass turbofan engine. We have read carefully all the comments and the explanations to the modifications are listed below.

Comment 1: Literature review & research design: solid. All the assumptions made during the study are thoroughly explained by references and no major unwarrantable hypotheses were made. A more detailed explanation about the working media properties is kindly requested, as the ideal gas assumption for the whole engine may affect the accuracy of performance simulations. The theoretical background of the paper is strong the study does not lack justification in any of the key areas.

Answer to comment 1: Although, the assumption that working fluids behave as ideal gases affects the precision in the value of the thermodynamic properties, this assumption provides an acceptable estimation of their properties, at the same time it makes the application of thermoeconomic theory more understandable for the purposes of the article.

Comment 2: English, figures, tables: the figures could be significantly improved in terms of aesthetics and readability. Moreover, the tables used at the manuscript can be revised to be more comprehensive by the reader. Concerning the use of English language, though, I suggest that the whole manuscript undergoes a grammar and syntax revision, preferably by a native English speaker. This will significantly improve the quality of the strong-all round, manuscript.

Answer to comment 2: A comprehensive review of English was carried out to improve grammar and syntax, as well as some improvements in the figures and tables of the manuscript. On the other hand, Tables 6 and 7 were placed in the appendix to improve the understanding and follow-up of the manuscript, while table 9 and 3 were removed from the text.

We attach the revised version of the manuscript.

Best regards.

 

Reviewer 2 Report

Authors detailly describe the residues cost formation of a high bypass turbofan
engine.
The description is too detailed, indeed, within the body paper. The paper is very long, costly to read and easy to get lost among many acronyms’ formulas within the text, lists of equations and too long tables. Authors must make a synthesis effort of the most relevant pieces of information to make the paper better understandable.
Some modifications I ask the authors to improve paper readability are:

1.- Move to the appendix data lists and tables that interrupt reading flow. For example: T6, t7, T9, T10 and T11. and discuss in body text main findings of the tables.

2.- Include acronyms and symbols meaning in the figures’ captions.

3.- Avoid the use of acronyms in the Abstract and in the Conclusions.

4.- Make the effort modifying abstract to be a better introduction to the paper and different from the conclusions (do not copy-paste from abstract to conclusions).

5.- Elaborate more the conclusions. Please, try to summarize the procedure, the most interesting discussions and highlight the best findings. The speech must flow through these steps. Please, do not just list things but elaborate from one step to another.

6.- At the end of the introduction, please, explain paper structure. Briefly (as briefly as possible) describe the content and purpose of every section.

It is also missing Sankey diagrams to better illustrate energy and exergy balances and flows of residues cost formation. Please, try to transform or complete your figures with Sankey diagrams that are better understood by majority of readers as a stander representation of energy (exergy flows).

Finally, avoid grouping references in the introduction. Please, separate every cited reference and discuss it individually.

Author Response

To Reviewer 2

We would like to thank  reviewer #2 for his valuable comments to improve our manuscript entitled: Residues cost formation of a high bypass turbofan engine. We have read carefully all the comments and the explanations to the modifications are listed below.

Comment 1: Move to the appendix data lists and tables that interrupt reading flow. For example: T6, t7, T9, T10 and T11. and discuss in body text main findings of the tables.

Answer to Comment 1: Some modifications were made to the text to improve its understanding. Among its main modifications were, placing Tables 6 and 7 in the appendix; while table 9 and figure 3 were removed from the text, to avoid interrupting the reading flow.

 

Comment 2: Include acronyms and symbols meaning in the figures’ captions.

Answer to Comment 3:Acronyms and symbols were included to improve the quality of the figures.

 

Comment 3: Avoid the use of acronyms in the Abstract and in the Conclusions.

Answer to Comment 3: The use of acronyms in the abstract and conclusions was omitted to avoid conflicts in the reading of the text.

 

Comment 4: Make the effort modifying abstract to be a better introduction to the paper and different from the conclusions (do not copy-paste from abstract to conclusions).

Answer to Comment 4: The introduction was improved to describe the content of the article globally.

 

Comment 5: Elaborate more the conclusions. Please, try to summarize the procedure, the most interesting discussions and highlight the best findings. The speech must flow through these steps. Please, do not just list things but elaborate from one step to another.

Answer to Comment 5: The elaboration of the conclusions and the procedure were improved to highlight the most important results obtained in the paper.

At the end of the introduction, please, explain paper structure. Briefly (as briefly as possible) describe the content and purpose of every section.

 Comment 6: In the introduction, the description of the paper structure and its purpose of each section was improved. It is also missing Sankey diagrams to better illustrate energy and exergy balances and flows of residues cost formation. Please, try to transform or complete your figures with Sankey diagrams that are better understood by majority of readers as a stander representation of energy (exergy flows).

Answer to Comment 6:  A Grassmman diagram was developed to observe more clearly the impact that internal and external irreversibilities (residues) of the processes have on obtaining the useful product of the system

We attach the revised version of the manuscript.

Best regards.

Author Response File: Author Response.pdf