Structural Design and Optimization of Herringbone Grooved Journal Bearings Considering Turbulent

Round 1

Reviewer 1 Report

In this work, the authors investigate the advantages of convergent Herringbone grooved Journal Bearings and the influence of bearing structure parameters on the static and dynamic performance of the bearing. the simulation is conducted using the finite difference method under a non-orthogonal coordinate system. The idea behind the work is promising and of interest to the readers. However, the paper should be edited and revised completely before considering it for publication in Applied Sciences Journal.

In the following, some recommendations regarding the paper:

1- A complete linguistic revision is needed.

2- All figures quality should be improved

3- All references should be revised and made according to the journal format.

4- Validation of the program is not sufficient, suitable with more recent and experiment papers.

5- It is suitable to add also the meshing size effect on the results.

6- the authors said that: the maximum error does not exceed 5%. Why this error is not significant? and how this value is calculated?

7- In the literature, there are more related and recent works that can be cited to situate correctly the main aim of your paper.

8- In the establishment of the equations, it is suitable to cite similar previous works to check easily your mathematical approach.

9- Interpretation of the results should be improved.

...

 

Author Response

Dear reviewer

Thanks for your comments. We have responsed to your comments and revised the manuscript according your comments . These changes in the new manuscript can be seen as follows.

Thanks  for your review!

Author Response File: Author Response.docx

Reviewer 2 Report

The paper presents mathematical optimization of grooved journal bearings lubricated by liquid metal assuming turbulent flow.

 

 Even though the mathematical approach seems right, the originality of the work and the application of the proposed solution seems unjustifiable. The results show the Herringbone groove is mathematically optimized without taking into consideration the manufacturability and viability of the proposed solution which is a red flag.

 

The turbulence regime is used but the authors need to compare the results with other approaches and justify why they have used a turbulent model and compare its merits.

 

The introduction section seems satisfactory  but the whole text should be re-reviewed for having a formal language throughout the manuscript.

 

This manuscript in the current format is not in the spectrum of Applied Science readers. 

Author Response

Dear reviewer

Thanks for your comments. We have responsed to your comments and revised the manuscript according your comments . These changes in the new manuscript can be seen as follows.

Thanks  for your review!

Author Response File: Author Response.docx

Reviewer 3 Report

This is an interesting paper regarding the scientific content but the quality of presentation can be severely improved. Please revise accordingly

• Please avoid abbreviations in abstract (e.g. what is the CT Tube?)
• In abstract, line 6, which are the two bearings?
• In abstract, there are numbers included which do not really make sense as the bearing geometry sets extent in large variety. Please refer using dimensionless parameters.
• Introduction, please avoid expressions like “The team of Professor…”, or “…team member…”, and just refer to the cited work [].
• Minor (and occasionally major) linguistic revisions are required: e.g. “It is precisely because…” does not make sense. Please perform a linguistic revision with a native English speaker.
• Please avoid using names in references in the text, e.g. “In the 1960s, Professor Hughes…”. Just use: In the 1960s it was found that the application of…load capacity [22].
• “...as a lubricant is almost blank”. What do the authors mean?
• “and the grooves designed in this paper of the herringbone grooved journal bearing are convergent”, please rephrase
• “The research object of this paper is the HGJBs.” The authors do not need to mention this at the beginning of each section.
• Figs 3, 4, 8, 9-15 must be larger and centered.
• “…so I won't repeat it here.” Please remove this phrase
• “When the journal changes little at the static equilibrium position”, please rephrase
• There are several references from Jurgen Schiffmann in HBJBs which may be added (some)

Author Response

Dear reviewer

Thanks for your comments. We have responsed to your comments and revised the manuscript according your comments . These changes in the new manuscript can be seen as follows.

Thanks  for your review!

Author Response File: Author Response.docx

Reviewer 4 Report

The manuscript of the article presents the results of numerical modeling of the lubrication process of the smooth surface of a plain bearing, in the design of which grooves are made in a herringbone pattern. The results of the article substantiate the requirements for a spherical CT X-ray tomograph tube, which has a high load capacity, high rigidity and good stability characteristics.The conclusions of the article are confirmed by the obtained numerical results.
The article is structured, contains a list of citations of modern articles devoted to issues related to the design of friction units and modeling of the bearing structure, lubrication processes.
To improve the quality of the article, a little editorial revision is required.
The extraneous character in Line 142 should be removed. It should probably be "end" instead.
The list of cited sources needs editing. References to cited publications should be brought to the form accepted in the journal.

Comments for author File: Comments.pdf

Author Response

Dear reviewer.Thank you for your comments. We have made corresponding changes based on your suggestions.

Author Response File: Author Response.docx

Reviewer 5 Report

The authors presented interesting work on the "Structural Design and Optimization of Herringbone grooved Journal Bearings Considering Turbulent".  The paper is accepted for publication. However, the quality of some figures should be improved. In addition, Please, revise and improve the conclusions.

Author Response

Dear reviewer.Thank you for your comments. We have made corresponding changes based on your suggestions.

Reviewer 6 Report

The study of the static and dynamic characteristics of a radial hydrodynamic bearing with a "herringbone" clearance profile was carried out. The article contains an extensive literature material, an analysis of the state of the problem is given, on the basis of which a conclusion is made about the prospects of using such bearings with liquid lubrication in devices for conducting tomography. The advantage of the study is that the authors did not limit themselves to studying laminar flows, but also studied turbulent flows.

The research presented in the article has some drawbacks and the reviewer has comments and questions that are outlined below.

1. On page 4, after equation (1), there are values ​​indicated in Chinese characters, which are unacceptable in the English text.
2. Authors use the abbreviation "HGJB", which first appears on page 4. But it is difficult to understand what it is. Most likely it is a bearing. The caption to Figure 1 contains the positions a, b, c. But what they mean is anyone's guess.
3. On page 5, the Reynolds equation (1) is given and the calculations for transforming it from one coordinate system to another are given, which looks superfluous. These equations are widely known, and one could immediately bring the equation in the required coordinate system.
4. The authors claim that page 6 contains the dimensionless dynamic Reynolds equation (4). However, the last term on the right-hand side of the equation is written using the dimensional quantities h and t.
5. Formula (10) contains the term γg, which depends on Cg. The latter is called "depth of the grooves". In reality, it must be some kind of rather complex mathematical structure, which really depends on the depth of the grooves, but is not only the depth. This dependence plays a decisive role in the calculations and their results, therefore the article should provide the exact dependence for Cg, where the coordinates of the selected system must obviously be present.
6. The integral formulas (14) and (15) cause some bewilderment. The authors claim that by substituting (11), (12) into these formulas, one can obtain (16). In our opinion, such conclusions cannot be drawn. It is difficult to understand how the pressure function P can be integrated using (14), (15) when it is not known in advance? In addition, it is not clear what is the region Lij in integrals (15).
7. And the explanation concerning the method of integration of the dynamic Reynolds equation “The solution method of dynamic Reynolds equation is similar to that of static Reynolds equation” looks completely unacceptable. The mathematical formulas given by the authors are most likely given in order to explain how they used some software product suitable for calculating such structures, but did not program the calculations themselves using a finite-difference mesh or the finite element method. Therefore, the explanations are of a formal nature, which aims to convince the reader that the authors themselves programmed the calculations. The task is too complicated for this to be limited to the given explanations.
8. Finally, formulas must have the same character size and Greek letters must be upright.

There are other remarks and questions of a similar nature, but the stated ones are enough. The presented article does not make a very good impression, and it would be necessary to make changes to the text and write what software product the authors used, without hiding its name, and give explanations on this account that would remove the doubts expressed.

Author Response

Dear reviewer.Thank you for your comments. We have made corresponding changes based on your suggestions.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I would like to thank the authors for their valuables responses to my comments. Based on the reviewer's recommendations, I think that the manuscript quality is significantly improved.  

 

 

Author Response

Dear reviewer.Thank you for your comments. We have made corresponding changes based on your suggestions.

Author Response File: Author Response.docx

Reviewer 2 Report

N/A

Author Response

Dear reviewer.Thank you for your comments. 

Author Response File: Author Response.docx

Reviewer 6 Report

The article can be accepted for publication in this revised form.