Numerical Analysis for Augmentation of Thermal Performance of Single-Phase Flow in Microchannel Heat Sink of Different Sizes with or without Micro-Inserts

COMMENT: Many thanks for your improvement. However, this manuscript is not suitable for publications! 

RESPONSE: Thank you very much for your comments that helped us to improve this manuscript.

COMMENT 1: It suffers from novelty. 

RESPONSE: While we appreciate the reviewer’s feedback, we respectfully disagree. This study makes a valuable contribution to the microchannel field because the findings of the present study describes the compound effect of two factors- that still are in nascent age- which helps to gain insights of further intensification of performance of microchannel.

COMMENT 2:  I can not see that it is written professionally! In one sentence several words were repeated! 

RESPONSE: Thanks for good assessment, the manuscript is revised/deleted/modified/restructured the words/sentences wherever needed.

COMMENT 3: Figures are not well prepared. They must be provided in vector based!  

RESPONSE: The Figures are modified in order to have readable scale bar. Also, y-axis of few figures has been enlarged.

COMMENT 4: It doesn’t have a good description for model and equation! They are just copied and pasted from somewhere! 

RESPONSE: Respected reviewer, equations has been developed from generalized form as per the model. All equations are typed in Microsoft word using equation tool.

COMMENT 5: It doesn’t have a good validation!  

RESPONSE: The validation is done from the results of experimental and numerical solutions with references cited in manuscript (Wang et al., 2019 [39]).

COMMENT 6:  Overall this paper is not acceptable for Fluids! 

RESPONSE: Thank you very much for your review and comments. They are quite valuable. I have gone through the whole manuscript and modified accordingly.

COMMENT:  This manuscript numerically analyzes the thermal performance of a single-phase flow in a microchannel heat sink with or without microinserts. In general, the article is interesting, seems well conducted and is written in a comprehensive manner.

RESPONSE: Thank you very much for your kind words of appreciation! We have read your comments carefully and tried our best to address them one by one and hope that the revised manuscript would meet your expectations.

COMMENT 1: A nomenclature table would be of great help for the reader.

RESPONSE: Thank you for the nice suggestion. The nomenclature table is added in the manuscript.

COMMENT 2: Even if the literature already contains a satisfactory number of citations. Avoid the use of lumping/overkilling citations such as: “several methods [9-11] including by applying appropriate working fluid [12-18]”.

RESPONSE: Thank you very much for pointing out this. The manuscript is revised by considering the types of shape, geometry, fluids, material and surface conditions, which are as follows:

“Several researchers have put their efforts towards enhancing thermal-hydrodynamic performance of microchannel by employing different techniques of varying- channel shape (wavy [9], tapered [10]); geometry (circular [11], rectangular [12], triangular [13], square [14]); working fluids (water [15], air [16], nano-fluids [17]); materials (silicon [18], copper [19]); and surface modifications (staggered [20], porous [21], ribs [22], sinusoidal wavy [23]).”

COMMENT 3: The quality of some figures should be improved. As an example, In Figure 1 or Figure 3c it is difficult to read the scale bar. In Figure 4 or Figure 10, y-axis should be enlarged to better identify represented values.

RESPONSE: As per the suggestions, modified Figure 1 or Figure 3c in order to have readable scale bar. In addition, in Figure 4 and Figure 10, y-axis has been enlarged.

COMMENT 4: All results corresponding to the same magnitude should be reported with the same number of decimals.

RESPONSE: Thanks for good suggestion. We agree that this is an important consideration. The changes are made in manuscript as per the suggestions.

COMMENT 5: Even if results are described in detail. In general, more contrast/comparison with literature should be desirable.

RESPONSE: Thanks for excellent suggestions. Added the suggested contents to the manuscript.

COMMENT 6: Conclusions are somewhat too long. I would outline results in a more synthetic manner.

RESPONSE: The conclusion in manuscript is modified as per the suggestion.

COMMENT 7: The style of several references should be improved. Take ref. 25 as an example.

RESPONSE: The entire references reviewed thoroughly and modified the necessary changes and followed the template of journal for formatting of references.

Reviewer #1

1

COMMENT: The temperature distribution and flow pattern shall be given and analyzed in detail

RESPONSE: As suggested, the temperature distribution and flow pattern have now been added in the revised manuscript.

2

COMMENT: The enhanced mechanism of the microinserts all be analyzed in detail.

RESPONSE: The details have now been added in manuscript as per suggestions

3

COMMENT: The dimensions of the microchannel and the microinserts need to be added.

RESPONSE: The dimensions have now been added as per suggestions

4

COMMENT: On Page 5, the definition of temperature difference is not given. If it refers to the difference of the maximal temperature and the input temperature, the simulation conditions for the grid independence test shall be corrected for the temperature difference is small, which may lead to an error.

RESPONSE: As suggested, the table of grid independence test has been modified and added in the revised manuscript.

COMMENT: The studied configuration is interesting, but the authors presented only qualitative results. This is the main issue with this work; thus, I recommend adding the 3D temperature fields and the 3D flow structures. In addition to some profiles at constant cross sections.

RESPONSE: The details have now been added as per suggestions

COMMENT: The boundary conditions are to be expressed mathematically.

RESPONSE: As suggested, the boundary conditions have now been added in the revised manuscript.

COMMENT: How the heat flux continuity is ensured at the interface between the fluid and the solids?

RESPONSE: At the interface between the fluid and the solids the temperature of the wall is set so that produce the same heat flux.

COMMENT: There are some misprints, to be corrected.

RESPONSE: As suggested, misprint is identified and corrected.

COMMENT: What are the properties of the solids? to be mentioned.

RESPONSE: For the present study, the property of the aluminum is considered for the analysis.

COMMENT: What are the considered inlet temperatures?

RESPONSE: For the present study, Inlet temperatures is taken as 303 K

COMMENT: Eq. 11 is very confusing (are you dividing by PP?).

RESPONSE: No, it’s at constant PP.

COMMENT: In the validation part, are the papers used for the comparison based on experimental works? If no replace validation by verification.

RESPONSE: Yes, the papers used for the comparison are based on experimental work.

COMMENT: In the validation part, What are the configurations studied in the works used for the validation/verification? Are all these configurations same?

RESPONSE: The configuration studied in the works for validation is of circular type that is same as of present study.

COMMENT: In the validation part, Why there is a very important difference between your results and the finding these works?

RESPONSE: The maximum deviation between experimental work of Wang et al. [39] and present simulation work data is within 14.6 %, indicating the numerical solution in the present work is reliable.

COMMENT: In the legend of Fig 4, use same referencing style as in the text.

RESPONSE: As suggested, Fig.4 has now been modified in the revised manuscript.

COMMENT: Are the properties of water considered as temperature independent?

RESPONSE: Yes, properties of water considered as temperature independent of the present study.

COMMENT: For all the considered configurations and Re number values the TPF is below 1. This means that the plain microchannel has better performances. What can you conclude?

RESPONSE: The values of TPF decreases because of rapid increment of friction factor ratio f/fs and decrease in Nusselt number ratio Nu/Nus with increasing Reynolds number. At lower range of Reynolds number TPF values is observed to be higher in case of with microinserts when compared with that of without microinserts for smallest channel size of 0.5 mm. At higher range of Reynolds number addition of microinserts has comparative TPF values with or without microinserts cases for a channel sizes.

COMMENT: Some physical interpretations are to be added to the discussion.

RESPONSE: As suggested, some physical interpretations have now been modified in the revised manuscript.

COMMENT: A nomenclature is to be added.

RESPONSE: In the manuscript, nomenclature of the required symbols/terms has been explained wherever it has been used.

COMMENT: Abstract must have reasonable structure but I couldn’t see that in your paper! We need to see some of your quantitative results! There must be some numbers!

RESPONSE: As suggested, abstract has now been modified and numeric result has been added in the revised manuscript.

COMMENT: Your title must be more specific!

RESPONSE: As suggested, title has now been modified in the revised manuscript.

COMMENT: Your novelty must clearly stated please avoid using general words!

RESPONSE: As suggested, novelty of the present work has now been added in specific terms related to my work.

COMMENT: All abbreviations must clearly defined in your paper! Even CFD!!!!!

RESPONSE: As suggested, all abbreviations are defined wherever is used.

COMMENT: Your equations are very general and must change to your specific case!

RESPONSE: As suggested, modified equation have now been added in the revised manuscript.

COMMENT: For figure 1, where are your coordinates!

RESPONSE: As suggested, coordinates in figure 1 have now been added in the revised manuscript.

COMMENT: Do not use screenshot for figure 3, please provide your own figures!

RESPONSE: The figures used are from ANSYS workbench on which the present work has been performed.

COMMENT: Please provide complete bibliographic data for your commercial software! Please properly cite it in your references!

RESPONSE: As suggested, software ANSYS has now been added in references in the revised manuscript.