Double-Diffusive Effects on the Onset of Rayleigh-Benard Convection of Water-Based Nanofluids

Round 1

Reviewer 1 Report

The paper describes a numerical simulation of a nanoparticle fluid in a rectangular cavity heated from below. The numerical discussion and figures are all reasonable. The grammar has some moderate issues which affect readability.

Author Response

First of all, the authors wish to thank the Reviewer for her/his valuable comments. The manuscript has been properly modified to address the reviewer’s requests.

A point-by-point response is provided in the following section.

1) All the manuscript has been revised for grammar errors and misprints.

Reviewer 2 Report

Massimo Corcione et al. have studied buoyancy-driven convection in enclosure filled with nanofluid and heated from below using a two-phase model based on the double-diffusive approach. Moreover, it is found that the dispersion of the nanoparticle into the base fluid increases remarkably the stability of the nanofluid layer. It is novel and interest to the researchers in the related areas. I would consider the paper for publication after minor revisions are made according to the following specific comments:

1.     Parts of the theoretical formulas are not cited. Just like formulas (8),(12),(13).

2.     In Fig. 3a, mostly the numerical values are less than the experimental data of Putra’s, why the opposite results achieved in the last one? Please explain it.

3.     In Fig. 4, why the spacing of the abscissa is inconsistent?

4.     This paper is well done in numerical simulations. In Introduction, for the study of experimental fluids and wettability, the authors may refer these recent papers: 1. Nano-Micro Lett. 14,97,2022; 2. Nanoscale, 2022,14, 9392

5.     For more perfection, several language mistakes could be revised.

Author Response

First of all, the authors wish to thank the Reviewer for her/his valuable comments. The manuscript has been properly modified to address the reviewer’s requests.

A point-by-point response is provided in the following section.

 1) The equation (8) is derived by the work of Brenner and Bielenberg for thermophoresis of aerosol particles. As concern the equations (12) and (13), the mixing theory is typically applied to nanofluids as made by several researchers, many of them just cited in the present article. The relevant references have been added in the revised text.

2) All the relative differences between the Putra and numerical data shown in fig 3 are lower than the experimental uncertainty declared by Putra. In particular, the points relative to the higher Rayleigh numbers are in a range of flow regime characterized by increasing turbulence, in which the flow behavior is less affected by the double-diffusive effects, as reported in the article cited in the text (ref [41]).

3) A new figure with thicker axis marks has been uploaded.

4) We thank the Reviewer for the valuable comment. Unfortunately, the suggested articles are not far pertinent with the onset of the Rayleigh-Benard convection, which is the main scope of the present study. However, these works, which are very interesting, can be taken in consideration for future works that our group is developing.

5) All the manuscript has been revised for grammar errors and misprints.

Reviewer 3 Report

See attached file.

Comments for author File: Comments.pdf

Author Response

First of all, the authors wish to thank the Reviewer for her/his valuable comments. The manuscript has been properly modified to address the reviewer’s requests.

A point-by-point response is provided in the following section.

1) We thank the Reviewer for the valuable comment. The article title has been changed: “Double-diffusive effects on the onset of Rayleigh-Benard convection of water-based nanofluids”.

2) The abstract has been revised.

3) A nomenclature of all parameters, with relative units, has been added at the end of the manuscript.

4) At the beginning to the introduction, a sentence to enumerate some engineering applications, for which the results of the present study may be useful, has been added. All the works cited in the introduction have been properly commented and discussed. Unfortunately, the suggested articles are not far pertinent with the onset of the Rayleigh-Benard convection, which is the main scope of the present study. However, these works, which are very interesting, can be taken in consideration for future works that our group is developing.

5) To respect the template of the journal, we prefer don’t change the title of the section.

6) A new sentence to define future work on same topic has been added at the end of the conclusions.

Round 2

Reviewer 3 Report

Accepted in the present form.