Experimental Study of the Formation and Evolution of Gas Jets in Supersonic Combustion Chambers

Round 1

Reviewer 1 Report

1. In the Abstract and Introduction sections, it is stated that the authors have introduced a simple and efficient flow field visualization method. Though, the common shadow imaging technique is used. Please emphasize the novelty of the imaging method or correct the statements.    2. In Figures 9 and 10, the authors imply that a single vortex is denoted by label 1. Given the complex turbulent flow structure, it is vague on what basis flow features denoted by 1 or 2 belong to single vortexes and how they were tracked in time. Here I suppose one can only speculate about some region in the shear layer containing at least several vortices.   3. How the velocity diagram presented in Figure 10 was obtained (orange arrows)?   4. For clearer representation, it is required to denote angles beta and theta in additional sketch figures or maybe in Figure 7.   5. Figure 12. It seems that plot symbols are different for the top image and the images underneath.    6. Thorough Language editing is in order. The manuscript contains a large number of typos and grammatical errors. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Experimental study presented in the proposed article has a high research quality. However, the document can be improved taking into account:

 

1.     Section 2.1.2 (Indicate where pressure, temperature and mass flow rate are being sensed) paper indicates “various parameters ….. collected during the test”.

2.     Use same units in the article.

 

3.     Authors can give to the lector a better idea in section 3.2 including a table which includes the results at different times.

Updated on 1.17 

What is the main question addressed by the research?

The research focused its study on the influence of jet angle and flux ratio in supersonic combustion (nitrogen).

 Is it relevant and interesting?

Nowadays, supersonic combustion it´s an important topic considering new technologies (Pulse detonation engines, Ramjets, pressure wave exchangers) further, research compares simulation with experimental results.

 How original is the topic?

Average. As I explained above, supersonic combustion it’s an actual research topic, reason why it’s possible to find different studies in the field of study.

 What does it add to the subject area compared with other published material?

• Provides a verification of the numerical simulations through experiments.
• Gives information regarding influence on the flow field shear vortex.
• Carried out supersonic combustion experiments with different jet angles and flux ratios.

Is the paper well written? Is the text clear and easy to read?

Although my English it´s not native; in my opinion paper is well written, however, some paragraphs are difficult to understand considering technical results given by authors.

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

In this study authors applied field visualization method to study jets in supersonic combustion chambers.

I look forward to seeing it in print following some minor revision.

1)      Adding nomenclature and definitions would make it easier for readers to understand

2)      different parameters.

3)      The authors cited to a paper for the caption of Figure 1. (Schematic diagram of a transverse jet inside the supersonic mainstream [8]). Please provide the copyright agreement or replace this figure with one that you made by yourself.

4)      In 2.1. Test system, please provide the uncertainties for each measurement.

 

5)      Typo-error in Line 164 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf