Study on the Characteristics of Boundary Layer Flow under the Influence of Surface Microstructure

Round 1

Reviewer 1 Report

The manuscript is well written by the authors and can be considered for publication after minor revisions, which are as follows:

1. English corrections are required throughout the manuscript
2. Although all the equations are given, no information was provided on near-wall treatment. Did the authors use the wall damping function?

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Reviewer 2 Report

The paper "Study on the Characteristics of Boundary Layer Flow under the Influence of Surface Microstructure" is very interesting. The results are novel. The paper is well-written and clearly organized. The paper is publishable after the minor revision.

Remarks:

1. Scale bar is necessary for Figure 1.
2. Scaling analysis will be useful for a reader. What are typical spatial and temporal scales, inherent for the reported processes?
3. Explicit values of the dimensionless values, relevant to the processes should be reported in the revised version of the manuscript. What is the value of the Reynolds number?

Author Response

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Reviewer 3 Report

The following aspects should be strenghtened before a final decision concerning publication of this paper could be made: 

[1] linguistic correction - please, read carefully the manuscript once more and polish some sentences, e.g. (cit.): "Since triangular grooves are longitudinal grooves arranged along the spanwise and extending along the flow, the wall surface of the grooves has a height difference in the spanwise direction, so the velocity distribution of triangular grooves cannot be comprehensively understood from the spanwise plane alone." - 4 x grooves; 

[2] methodological question - what specific numerical method is behind a solution to the flow problem - one may find precise information about an application of the software FLUENT and meshing, but flow problems are solved with the use at least Finite Element Method or Finite Volume Method (at least) - approximating functions and solver parameters have not been specified; 

[3] what can be said about validation of these results? The Authors have made some conclusions at the end, but numerical and modelling error have not been discussed before; 

[4] novelty of the paper needs to be better highlighted as this is not the first work concerning this matter for sure; 

[5] physical aspects - is it physically justified that physical and material parameters can be treated as temperature-independent here? - high velocities induce for sure heating of the surface (some aeronautical engineering failures proved this fact). 

Author Response

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Reviewer 4 Report

Authors have presented an article entitled “Study on the Characteristics of Boundary Layer Flow under the Influence of Surface Microstructure” Though the manuscript is well written and organized but there is scope for further improving the quality of the draft before considering for publication.  

Few comments are listed below:

1.      In the Abstract section author mention about 10% shear force reduction in the subsonic range. Please elaborate the reason behind it.

2.      Author should use full form of abbreviation (such as LES etc.) when it is used first time on the Keywords or any other section.

3.      As author mentioned that “the friction increases when the speed is below 0.8Ma and 649 decreases when the speed is above 0.8Ma” Is 0.8 MPa is the critical limit for only triangular groove structure?

Authors have nicely presented the results with a major highlighted corrections. They should also check the typos and grammatical mistakes in the revised version

 

Author Response

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Round 2

Reviewer 3 Report

This paper is now ready for publication in the journal. The Authors are encouraged to submit their figures in higher resolution. 

Author Response

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