2D Numerical Study on the Flow Mechanisms of Boundary Layer Ingestion through Power-Based Analysis
Round 1
Reviewer 1 Report
Attached.
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.Author Response File: 
Author Response.docx
Reviewer 2 Report
Manuscript title: 2D numerical study on the flow mechanisms of boundary layer ingestion through power based analysis
General Comments:
This study is a power bookkeeping analysis to quantify the power terms in laminar jet and also boundary layer ingestion of some numerical simulations. The case studies are 2D laminar jet, 2D laminar boundary layer over a flat plate, an actuator disc and an integrated vehicle model, plus 2D turbulent boundary layer over a flat plate and an integrated vehicle using RANS simulation with k-ω-sst model. Although the study is interesting in propulsion systems, the manuscript can not be published in the present format; specifically the introduction, the results and the discussions, therefore the manuscript needs major modifications. Here are the comments below.
Major modifications:
- The introduction does not properly express the need for a power analysis, and the importance of this analysis in propulsion systems.
- It has not been explained the evolution of the power analysis, what are the advantages and the drawbacks of these analysis, what has been done and what is missing; in the other word, what and where is the gap which motivated the authors to carry out this study.
- There are only two references: “Drela [8] introduced the power balance method to demonstrate that BLI reduces the viscous dissipation of the aircraft wake and the propulsive jet. Arntz, Atinault [9] advanced this method by including thermal power.” Is not there any other work? What have they done exactly? What have been the benefits, challenges, and the drawbacks?
- The equations have been written without any references. It is not clear whether the authors derived any equation or they just wrote the equations which have already been derived.
- The simulations have been performed with different resolutions, and the simulations with the finest grid resolution were considered as a reference, while the simulations need to be validated with other references such as experiments or previously published numerical simulations or analytical solutions.
- For each case study, there should be some discussions about the power analysis of a similar case which have already been done before. Only in section 3.2 the results of the simulation over the flat plate were discussed in a comparison with some references: “This portion of wake is slightly higher than the value given by Drela (about 21%) [8].”
Minor modifications:
- There are several typos and grammatically incorrect sentences, such as “to reduces fuel consumption”, “aircraft which fuselage is merged”, etc. There are also some letters which should not have been written in capital, such as “As a result, the ratio Ėw/ DV∞ ”.
- Figure 10 must be replaced by Figure 8 in “Figure 10 visualizes the power bookkeeping of the actuator disc.” In line 294
- Some notations have not been explained. For example, what is T here? “To maintain a perfect equilibrium (T=D) is tricky in this simulation”.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
There are still some typos and grammatical issues. Examples are "apples (should be "applies") on page 12 and "on the other hand side" on page 20. Additionally, they keep changing referring to the same boundary condition as "no-slip" and "non-slip". It is better if they keep one language.
Author Response
We fix the typos and grammatical issues pointed out by the reviewer. Thanks for the corrections.
Reviewer 2 Report
The introduction has been improved significantly although the citations need to be corrected, and more results have been brought and discussed in the new manuscript. The manuscript now has the quality to be published. Congratulations to the authors.
Author Response
Suggestions from the reviewer to improve the introduction are very much appreciated. We have inspected the citations and corrected them accordingly.
