Numerical Analysis of a Self-Acting Gas Bearing Lubricated with a Low-Boiling-Point Medium Using an Advanced Model Based on the Finite Difference Methods and Universal Computational Fluid Dynamics Software

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1 There are many ancient documents in the reference literature, and the analysis of the latest research progress is not sufficient.

2 Two simulation methods are used for simulation analysis, and the results are highly similar. ANSYS CFX is a common simulation software, which will optimize and simplify the settings during the simulation process, resulting in the deviation between the simulation results and the actual measurement results. The results obtained by the two methods in this paper are highly similar, so how to prove the accuracy and reliability of GAZBEAR?

3 There is a lack of calculation results in this paper, and tables should be added to show the simulation values in detail.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors presented a Numerical study on the self-acting gas bearing lubricated with a low-boiling-point medium. The paper is generally well written and has good scientific soundness.

The introduction should be improved by adding the main quantitative results.

The sub-title ‘’ Characteristics of the research object’’ is confusing, better to change it

The 3D governing equations and associated boundary conditions solved via ANSYS should be presented and described?

What is the used turbulence model?

Several information related to the numerical procedure, like the convergence criterion, time step … are missing

It is mandatory to verify/validate (comparison with previously published results) the CFD model, in addition a grid sensitivity test is to be performed

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In this paper, a numerical analysis method based on finite difference method for self-acting gas bearings lubricated by low-boiling-point medium is presented, and the pressure distribution and the reaction force of lubricating film are calculated by using a general CFD program. The conclusion of this paper shows that the numerical results obtained by the two different methods are highly consistent, and either method can be used for the analysis of gas bearings. The first method must have professional knowledge of gas bearing models and analysis methods, but the advantage is that the calculation speed is fast, and the second method is easier to get results based on the general CFD program, but the speed is slower. For improving the quality of the manuscript, some suggestions are listed for the authors as follows:

1. In section 1，it should be noted that the same literature has been cited many times in different contents and locations of the article, whether the cited literature is accurate？there are two places in the second and third paragraphs of the introduction where the format of the citation sequence number is inconsistent with other formats.

2. In section 4, whether The point marked with the nominal value of aerodynamic lift in Figure 2 can express the view more clearly, and "The results of the calculations showed that the bearing is capable of carrying significantly higher forces than the nominal static load of 18 N. "Is it rigorous to draw this conclusion only from Figure 2? Are there other factors that limit the load it can bear? Detailed and clear explanation is needed.

3. In Section 4, it can be seen from Figure 3 that there is a large gap between 90° and 180°, but why is the minimum pressure not in this range in Figure 4?Detailed and clear explanation is needed.

4. "Figure. 10(b) vectors indicating the flow directions." The vector expression is not clear.

5. This paper assumes that the gas is laminar flow, but the nominal speed is set to 40000rpm during the design. Will this assumption cause too much distortion in the simulation results?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The quality of the revised paper has been improved and can be published in journals.

Comments on the Quality of English Language

The quality of the revised paper has been improved and can be published in journals.

Reviewer 3 Report

Comments and Suggestions for Authors

It is recommended to align the image axes in Figures 10a and b