Abstract

Purpose The purpose of this paper is to study the pumping efficiency of oil seals with different surface textures at different speeds, and the influence of the rotation direction of triangular texture on the sealing performance was further analyzed.Design/methodology/approach Based on the theory of elastohydrodynamic lubrication and the pumping mechanism of rotary shaft seals, establishing a numerical model of mixed lubrication in oil seal sealing area. The model is coupled with the lip surface texture parameters and the two-dimensional average Reynolds equation considering the surface roughness.Findings The results show that the application of lip surface texture technology has obvious influence on the oil film thickness, friction torque and pumping rate of oil seal. The triangular texture has the most significant effect on the increase of pump suction rate. When the rotation direction of triangular texture is 315 degrees, the pumping rate of oil seal is the largest compared with the other seven directions.Originality/value The model has a comprehensive theoretical guidance for the design of new oil seal products, which provides a certain basis for the application of surface texture technology in the field of sealing in the future.Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0198/


Authors

Zhang, Fuying;  Zhang, Yuanhao

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  • 3 reviewers
  • pre-publication peer review (FINAL ROUND)
    Decision Letter
    2020/08/07

    07-Aug-2020

    Dear Zhang, Fuying; zhang, yuanhao

    It is a pleasure to accept your manuscript ilt-06-2020-0198.R2, entitled "Research on Sealing Performance of Oil Seals with Micro-dimple Texture on Lips" in its current form for publication in Industrial Lubrication and Tribology. Please note, no further changes can be made to your manuscript.

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    Thank you for your contribution. On behalf of the Editors of Industrial Lubrication and Tribology, we look forward to your continued contributions to the Journal.

    Sincerely,
    Prof. Carsten Gachot
    Editor, Industrial Lubrication and Tribology
    carsten.gachot@tuwien.ac.at

    Decision letter by
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    Reviewer report
    2020/08/07

    No further comments.

    Reviewed by
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    Reviewer report
    2020/08/06

    I am satisfied with the changes done by the authors.

    Reviewed by
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    Author Response
    2020/08/06

    Dear Editors and Reviewers:
    Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Research on Sealing Performance of Oil Seals with Micro-dimple Texture on Lips” (ID: ilt-06-2020-0198.R1 ). We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the Editorial comments are as flowing:

    Responds to the Editorial comments: Please correct the format of the references and keep the reference list more up-to-date.
    Response: We have modified the format of the references in the paper according to the requirements of the journal. Please check it.

    We appreciate for Editors and Reviewers’ warm work earnestly, and hope that the correction will meet with approval. Once again, thank you very much for your comments and suggestions.



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  • pre-publication peer review (ROUND 2)
    Decision Letter
    2020/07/31

    31-Jul-2020

    Dear Prof. Zhang:

    Manuscript ID ilt-06-2020-0198.R1 entitled "Research on Sealing Performance of Oil Seals with Micro-dimple Texture on Lips" which you submitted to the Industrial Lubrication and Tribology, has been reviewed. The comments of the reviewer(s) are included at the bottom of this letter.

    Editorial comments:

    Please correct the format of the references and keep the reference list more up-to-date.

    Thanks a lot.

    To revise your manuscript, log into https://mc.manuscriptcentral.com/ilt and enter your Author Centre, where you will find your manuscript title listed under "Manuscripts with Decisions." Under "Actions," click on "Create a Revision." Your manuscript number has been appended to denote a revision.

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    Once again, thank you for submitting your manuscript to the Industrial Lubrication and Tribology and I look forward to receiving your revision.

    Sincerely,
    Prof. Carsten Gachot
    Editor, Industrial Lubrication and Tribology
    carsten.gachot@tuwien.ac.at

    Reviewer(s)' Comments to Author:
    Reviewer: 1

    Comments to the Author
    I am satisfied with the changes done by the authors.

    Reviewer: 2

    Comments to the Author
    No further comments.
    Reviewer: 1

    Recommendation: Accept

    Comments:
    I am satisfied with the changes done by the authors.

    Additional Questions:
    Originality: Does the paper contain new and significant information adequate to justify publication?: Publication is justified.

    Relationship to Literature: Does the paper demonstrate an adequate understanding of the relevant literature in the field and cite an appropriate range of literature sources? Is any signficant work ignored?: An adequate overview of literature is given.

    Methodology: Is the paper's argument built on an appropriate base of theory, concepts, or other ideas? Has the research or equivalent intellectual work on which the paper is based been well designed? Are the methods employed appropriate?: The numerical methodology seems to be adequate.

    Results: Are results presented clearly and analysed appropriately? Do the conclusions adequately tie together the other elements of the paper?: Results are properly presented and discussed.

    Practicality and/or Research implications: Does the paper identify clearly any implications for practice and/or further research? Are these implications consistent withthe findings and conclusions of the paper?: Implications are consistent with findings.

    Quality of Communication: Does the paper clearly express its case, measured against the technical language of the field and the expected knowledge of the journal's readership? Has attention been paid to the clarity of expression and readability, such as sentence structure, jargon use, acronyms, etc.: Adequate.

    Reproducible Research: If appropriate, is sufficient information, potentially including data and software, provided to reproduce the results and are the corresponding datasets formally cited?: Given.

    This journal is participating in Publons Transparent Peer Review. By reviewing for this journal, you agree that your finished report, along with the author’s responses and the Editor’s decision letter, will be linked to from the published article to where they appear on Publons, if the paper is accepted. If you have any concerns about participating in the Transparent Peer Review pilot, please reach out to the journal’s Editorial office. Please indicate below, whether you would like your name to appear with your report on Publons by indicating yes or no. All peer review content displayed here will be covered by a Creative Commons CC BY 4.0 license.: No, I would not like my name to appear with my report on Publons

    Reviewer: 2

    Recommendation: Accept

    Comments:
    No further comments.

    Additional Questions:
    Originality: Does the paper contain new and significant information adequate to justify publication?: Yes.

    Relationship to Literature: Does the paper demonstrate an adequate understanding of the relevant literature in the field and cite an appropriate range of literature sources? Is any signficant work ignored?: Yes.

    Methodology: Is the paper's argument built on an appropriate base of theory, concepts, or other ideas? Has the research or equivalent intellectual work on which the paper is based been well designed? Are the methods employed appropriate?: Yes.

    Results: Are results presented clearly and analysed appropriately? Do the conclusions adequately tie together the other elements of the paper?: Yes.

    Practicality and/or Research implications: Does the paper identify clearly any implications for practice and/or further research? Are these implications consistent withthe findings and conclusions of the paper?: Yes.

    Quality of Communication: Does the paper clearly express its case, measured against the technical language of the field and the expected knowledge of the journal's readership? Has attention been paid to the clarity of expression and readability, such as sentence structure, jargon use, acronyms, etc.: Yes.

    Reproducible Research: If appropriate, is sufficient information, potentially including data and software, provided to reproduce the results and are the corresponding datasets formally cited?:

    This journal is participating in Publons Transparent Peer Review. By reviewing for this journal, you agree that your finished report, along with the author’s responses and the Editor’s decision letter, will be linked to from the published article to where they appear on Publons, if the paper is accepted. If you have any concerns about participating in the Transparent Peer Review pilot, please reach out to the journal’s Editorial office. Please indicate below, whether you would like your name to appear with your report on Publons by indicating yes or no. All peer review content displayed here will be covered by a Creative Commons CC BY 4.0 license.: No, I would not like my name to appear with my report on Publons

    Decision letter by
    Cite this decision letter
    Reviewer report
    2020/07/31

    No further comments.

    Reviewed by
    Cite this review
    Reviewer report
    2020/07/20

    I am satisfied with the changes done by the authors.

    Reviewed by
    Cite this review
    Author Response
    2020/07/17

    List of Responses

    Dear Editors and Reviewers:

    Thank you for your letter and for the reviewer(s)’ comments concerning our manuscript entitled “Research on Sealing Performance of Oil Seals with Micro-dimple Texture on Lips” (ID: ilt-06-2020-0198 ).Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer(s)’ comments are as flowing:

    Responds to the reviewer(s)’ comments:

    Reviewer #1:

    1. Response to comment: A Brief literature overview is given. However, the research gap to be closed by this paper should be better worked out.
      Response: We are very sorry for the lack of literature. We have studied the relevant literature and supplemented the literature review.

    2. Response to comment: English writing and grammar Need to be improved. Just one example out of some: "Obtaining the the Change […]" (l. 12)
      Response: We are very sorry for our incorrect writing and corrected them.

    3. Response to comment: The description of the numerical model is quite scarce despite the complexity of the model. Here you should add some more detail and precision, for example by using a numerical flow chart.
      Response: We have made correction according to the Reviewer’s comments. We describe the numerical model and use the numerical flow chart.

    4. Response to comment: Circular, square and triangle textures were studied. The triangles were further rotated. However, the geomerical parameters in terms of width, depth and lateral distance are kept constant. Therefore one must be very careful in the interpretation of the results and statements about the advantages of certain geometries. The proper way would be to first optimize the dimensions of the individual geometries for themselves and then compare their optima, see Etsion (Modeling of Surface texturing in hydrodynamic lubrication, Friction 2013 1(3), 195–209). In view of this, the paper should be revised.
      Response: We carefully read the literature you suggested and added it to the references. However, this paper mainly studies the influence of the rotation direction of the surface texture of equilateral triangle on the sealing performance of oil seal, so we will further study your suggestions in the future.

    Special thanks to you for your good comments.

    Reviewer #2:

    1. Response to comment: The literature survey is not very comprehensive. For example, there is a recent review about surface texturing in machine elements which could be referenced: A. Rosenkranz et al., Adv. Eng. Mater. 2019, 21, 1900194.
      Response: We are very sorry for the lack of literature. We carefully studied the relevant literature and supplemented the literature review, and introduced the literature you suggested into our references.

    2. Response to comment: The introduction should be expanded and literature about the influence of surface textures on sealing performance should be added. Also, the authors should explain in more detail what their own research is about in the introduction. Furthermore, the authors should explain the novelty of the proposed research and the differences to similar studies which have been done in the past.
      Response: As you suggested, we have added relevant literature in the introduction and provided a supplementary description of our research and innovation.

    3. Response to comment: On what basis were the texture shapes and dimensions selected?
      Response: For the selection of texture shape, we are based on previous scholars' research, and the choice of texture size is because the texture parameters need to be coupled with the two-dimensional Reynolds equation considering the surface roughness peak, and the roughness size is very small, so in order to calculate the results more accurately, the selected texture size parameters are also smaller. The above is explained in detail in this paper.

    4. Response to comment: Fig. 3 is merely described and no discussion is offered.
      Response: We have modified the structure of the article, and the figure 3 you mentioned has become figure 4, and we have discussed the diagram in the article.

    5. Response to comment: Fig. 4: Why have oil seals with textures on their lip a larger pumping rate and why is the triangular texture performing the best?
      Response: As a result of our changes to the structure of the article, figure 4 you mentioned has become figure 5. Because the effective surface structure can improve the hydrodynamic pressure, increase the film thickness, reduce the viscous shear force and reduce friction. Therefore, the oil seal with texture on the lip performs better. At the same time, the triangle structure along the y-axis is asymmetric, one edge points to the sealing side, and the rest faces the surrounding side, which makes the pressure distribution pump the lubricant to the sealing side, overcomes more leakage and pumps more lubricant back to the sealing side, so as to improve the pumping rate. The above problems are explained in the paper.

    6. Response to comment: Fig. 5: Again, no discussion but merely a description! Please add a discussion to your findings!
      Response: We have changed the structure of the article. The picture 5 you mentioned has become picture 7. We are very sorry for the lack of our discussion. According to your suggestion, we have supplemented the discussion in the article. Please check it.

    7. Response to comment: Fig. 6(c): What do you mean with “change of rotation direction […] has little effect on roughness”?
      Response: As a result of our changes to the structure of this article, Figure 6 (c) you mentioned has become figure 8 (c). We are sorry for the error of our expression. It should be that the change of rotation direction has little influence on the surface morphology, and we have made some modifications in the paper.

    8. Response to comment: Fig. 6(d): More discussion is needed!
      Response: Due to the change in the structure of the article, Figure 6 (d) you mentioned has become figure 8 (d). Related discussion has been added to the article, please check it.

    Special thanks to you for your good comments.

    We appreciate for Editors/Reviewers’ warm work earnestly, and hope that the correction will meet with approval.
    Once again, thank you very much for your comments and suggestions.



    Cite this author response
  • pre-publication peer review (ROUND 1)
    Decision Letter
    2020/06/23

    23-Jun-2020

    Dear Mr. zhang:

    Manuscript ID ilt-06-2020-0198 entitled "Research on Sealing Performance of Oil Seals with Micro-dimple Texture on Lips" which you submitted to the Industrial Lubrication and Tribology, has been reviewed. The comments of the reviewer(s) are included at the bottom of this letter.

    The reviewer(s) have recommended major revisions to the submitted manuscript, before it can be considered for publication. Therefore, I invite you to respond to the reviewer(s)' comments and revise your manuscript.

    To revise your manuscript, log into https://mc.manuscriptcentral.com/ilt and enter your Author Centre, where you will find your manuscript title listed under "Manuscripts with Decisions." Under "Actions," click on "Create a Revision." Your manuscript number has been appended to denote a revision.

    You will be unable to make your revisions on the originally submitted version of the manuscript. Instead, revise your manuscript using a word processing program and save it on your computer. Please also highlight the changes to your manuscript within the document by using the track changes mode in MS Word or by using bold or coloured text.

    Once the revised manuscript is prepared, you can upload it and submit it through your Author Centre. The deadline for uploading a revised manuscript is 21-Sep-2020 from receiving this email. If it is not possible for you to resubmit your revision within this timeframe, we may have to consider your paper as a new submission.

    When submitting your revised manuscript, you will be able to respond to the comments made by the reviewer(s) in the space provided. You can use this space to document any changes you make to the original manuscript. In order to expedite the processing of the revised manuscript, please be as specific as possible in your response to the reviewer(s).

    IMPORTANT: Your original files are available to you when you upload your revised manuscript. Please delete any redundant files before completing the submission.

    Please note that Emerald requires you to clear permission to re-use any material not created by you. If there are permissions outstanding, please send these to Emerald as soon as possible. Emerald is unable to publish your paper with permissions outstanding.

    To help support you on your publishing journey we have partnered with Editage, a leading global science communication platform, to offer expert editorial support including language editing and translation.
    If your article has been rejected or revisions have been requested, you may benefit from Editage’s services. For a full list of services, visit: authorservices.emeraldpublishing.com/
    Please note that there is no obligation to use Editage and using this service does not guarantee publication.

    Once again, thank you for submitting your manuscript to the Industrial Lubrication and Tribology and I look forward to receiving your revision.

    Sincerely,
    Prof. Carsten Gachot
    Editor, Industrial Lubrication and Tribology
    carsten.gachot@tuwien.ac.at

    Editorial comments:

    Please carefully check the existing literature in order to provide a proper state of the art and to work out the novelty of this study. Overall, the discussion of the obtained results must be improved in order to make the manuscript suitable for publication in ILT.

    Reviewer(s)' Comments to Author:
    Reviewer: 1

    Comments to the Author
    The paper is about the numerical prediction of lip seal pumping rates with different surface texture. Against the background of the many works on Surface texturing, this simulation model could be of interest for the scientific community.
    Before acceptance, the following Points have to be addressed:

    1. A Brief literature overview is given. However, the research gap to be closed by this paper should be better worked out.

    2. English writing and grammar Need to be improved. Just one example out of some: "Obtaining the the Change […]" (l. 12)

    3. The description of the numerical model is quite scarce despite the complexity of the model. Here you should add some more detail and precision, for example by using a numerical flow chart.

    4. Circular, square and triangle textures were studied. The triangles were further rotated. However, the geomerical parameters in terms of width, depth and lateral distance are kept constant. Therefore one must be very careful in the interpretation of the results and statements about the advantages of certain geometries. The proper way would be to first optimize the dimensions of the individual geometries for themselves and then compare their optima, see Etsion (Modeling of Surface texturing in hydrodynamic lubrication, Friction 2013 1(3), 195–209). In view of this, the paper should be revised.

    Reviewer: 2

    Comments to the Author
    The manuscript deals with the theoretical investigation of textured oil seals. In particular the oil film thickness, friction, and pumping rate of an oil seal with different surface textures are modelled. The topic of the investigation might be interesting for the community. However, throughout the manuscript there is almost no discussion about the observed effects, which is why publication cannot be recommended.

    • The literature survey is not very comprehensive. For example, there is a recent review about surface texturing in machine elements which could be referenced: A. Rosenkranz et al., Adv. Eng. Mater. 2019, 21, 1900194.
    • The introduction should be expanded and literature about the influence of surface textures on sealing performance should be added. Also, the authors should explain in more detail what their own research is about in the introduction. Furthermore, the authors should explain the novelty of the proposed research and the differences to similar studies which have been done in the past.
    • On what basis were the texture shapes and dimensions selected?
    • Fig. 3 is merely described and no discussion is offered.
    • Fig. 4: Why have oil seals with textures on their lip a larger pumping rate and why is the triangular texture performing the best?
    • Fig. 5: Again, no discussion but merely a description! Please add a discussion to your findings!
    • Fig. 6(c): What do you mean with “change of rotation direction […] has little effect on roughness”?
    • Fig. 6(d): More discussion is needed!
      Reviewer: 1

    Recommendation: Major Revision

    Comments:
    The paper is about the numerical prediction of lip seal pumping rates with different surface texture. Against the background of the many works on Surface texturing, this simulation model could be of interest for the scientific community.
    Before acceptance, the following Points have to be addressed:

    1. A Brief literature overview is given. However, the research gap to be closed by this paper should be better worked out.

    2. English writing and grammar Need to be improved. Just one example out of some: "Obtaining the the Change […]" (l. 12)

    3. The description of the numerical model is quite scarce despite the complexity of the model. Here you should add some more detail and precision, for example by using a numerical flow chart.

    4. Circular, square and triangle textures were studied. The triangles were further rotated. However, the geomerical parameters in terms of width, depth and lateral distance are kept constant. Therefore one must be very careful in the interpretation of the results and statements about the advantages of certain geometries. The proper way would be to first optimize the dimensions of the individual geometries for themselves and then compare their optima, see Etsion (Modeling of Surface texturing in hydrodynamic lubrication, Friction 2013 1(3), 195–209). In view of this, the paper should be revised.

    Additional Questions:
    Originality: Does the paper contain new and significant information adequate to justify publication?: Novel insights about the effects of surface textures or their beneficial design is somewhat limited.

    Relationship to Literature: Does the paper demonstrate an adequate understanding of the relevant literature in the field and cite an appropriate range of literature sources? Is any signficant work ignored?: An adequate overview of literature is given, the Research gap to be closed with this paper remains unclear.

    Methodology: Is the paper's argument built on an appropriate base of theory, concepts, or other ideas? Has the research or equivalent intellectual work on which the paper is based been well designed? Are the methods employed appropriate?: The numerical methodology seems to be adequate but needs to be described in more Detail.

    Results: Are results presented clearly and analysed appropriately? Do the conclusions adequately tie together the other elements of the paper?: Results are properly presented but more discussion of them is highly recommended.

    Practicality and/or Research implications: Does the paper identify clearly any implications for practice and/or further research? Are these implications consistent withthe findings and conclusions of the paper?: Implications are consistent with findings.

    Quality of Communication: Does the paper clearly express its case, measured against the technical language of the field and the expected knowledge of the journal's readership? Has attention been paid to the clarity of expression and readability, such as sentence structure, jargon use, acronyms, etc.: The language needs to be improved.

    Reproducible Research: If appropriate, is sufficient information, potentially including data and software, provided to reproduce the results and are the corresponding datasets formally cited?: Generally given when the numerical model is described in more detail. Also more Information for the mixed lubrication model (surface sarameters) are necessary.

    This journal is participating in Publons Transparent Peer Review. By reviewing for this journal, you agree that your finished report, along with the author’s responses and the Editor’s decision letter, will be linked to from the published article to where they appear on Publons, if the paper is accepted. If you have any concerns about participating in the Transparent Peer Review pilot, please reach out to the journal’s Editorial office. Please indicate below, whether you would like your name to appear with your report on Publons by indicating yes or no. All peer review content displayed here will be covered by a Creative Commons CC BY 4.0 license.: No, I would not like my name to appear with my report on Publons

    Reviewer: 2

    Recommendation: Reject & Resubmit

    Comments:
    The manuscript deals with the theoretical investigation of textured oil seals. In particular the oil film thickness, friction, and pumping rate of an oil seal with different surface textures are modelled. The topic of the investigation might be interesting for the community. However, throughout the manuscript there is almost no discussion about the observed effects, which is why publication cannot be recommended.

    • The literature survey is not very comprehensive. For example, there is a recent review about surface texturing in machine elements which could be referenced: A. Rosenkranz et al., Adv. Eng. Mater. 2019, 21, 1900194.
    • The introduction should be expanded and literature about the influence of surface textures on sealing performance should be added. Also, the authors should explain in more detail what their own research is about in the introduction. Furthermore, the authors should explain the novelty of the proposed research and the differences to similar studies which have been done in the past.
    • On what basis were the texture shapes and dimensions selected?
    • Fig. 3 is merely described and no discussion is offered.
    • Fig. 4: Why have oil seals with textures on their lip a larger pumping rate and why is the triangular texture performing the best?
    • Fig. 5: Again, no discussion but merely a description! Please add a discussion to your findings!
    • Fig. 6(c): What do you mean with “change of rotation direction […] has little effect on roughness”?
    • Fig. 6(d): More discussion is needed!

    Additional Questions:
    Originality: Does the paper contain new and significant information adequate to justify publication?: Yes.

    Relationship to Literature: Does the paper demonstrate an adequate understanding of the relevant literature in the field and cite an appropriate range of literature sources? Is any signficant work ignored?: No.

    Methodology: Is the paper's argument built on an appropriate base of theory, concepts, or other ideas? Has the research or equivalent intellectual work on which the paper is based been well designed? Are the methods employed appropriate?: Yes.

    Results: Are results presented clearly and analysed appropriately? Do the conclusions adequately tie together the other elements of the paper?: Yes.

    Practicality and/or Research implications: Does the paper identify clearly any implications for practice and/or further research? Are these implications consistent withthe findings and conclusions of the paper?: Yes.

    Quality of Communication: Does the paper clearly express its case, measured against the technical language of the field and the expected knowledge of the journal's readership? Has attention been paid to the clarity of expression and readability, such as sentence structure, jargon use, acronyms, etc.: No.

    Reproducible Research: If appropriate, is sufficient information, potentially including data and software, provided to reproduce the results and are the corresponding datasets formally cited?:

    This journal is participating in Publons Transparent Peer Review. By reviewing for this journal, you agree that your finished report, along with the author’s responses and the Editor’s decision letter, will be linked to from the published article to where they appear on Publons, if the paper is accepted. If you have any concerns about participating in the Transparent Peer Review pilot, please reach out to the journal’s Editorial office. Please indicate below, whether you would like your name to appear with your report on Publons by indicating yes or no. All peer review content displayed here will be covered by a Creative Commons CC BY 4.0 license.: No, I would not like my name to appear with my report on Publons

    Decision letter by
    Cite this decision letter
    Reviewer report
    2020/06/23

    The manuscript deals with the theoretical investigation of textured oil seals. In particular the oil film thickness, friction, and pumping rate of an oil seal with different surface textures are modelled. The topic of the investigation might be interesting for the community. However, throughout the manuscript there is almost no discussion about the observed effects, which is why publication cannot be recommended.

    • The literature survey is not very comprehensive. For example, there is a recent review about surface texturing in machine elements which could be referenced: A. Rosenkranz et al., Adv. Eng. Mater. 2019, 21, 1900194.
    • The introduction should be expanded and literature about the influence of surface textures on sealing performance should be added. Also, the authors should explain in more detail what their own research is about in the introduction. Furthermore, the authors should explain the novelty of the proposed research and the differences to similar studies which have been done in the past.
    • On what basis were the texture shapes and dimensions selected?
    • Fig. 3 is merely described and no discussion is offered.
    • Fig. 4: Why have oil seals with textures on their lip a larger pumping rate and why is the triangular texture performing the best?
    • Fig. 5: Again, no discussion but merely a description! Please add a discussion to your findings!
    • Fig. 6(c): What do you mean with “change of rotation direction […] has little effect on roughness”?
    • Fig. 6(d): More discussion is needed!

    Reviewed by
    Cite this review
    Reviewer report
    2020/06/21

    The paper is about the numerical prediction of lip seal pumping rates with different surface texture. Against the background of the many works on Surface texturing, this simulation model could be of interest for the scientific community.
    Before acceptance, the following Points have to be addressed:

    1. A Brief literature overview is given. However, the research gap to be closed by this paper should be better worked out.

    2. English writing and grammar Need to be improved. Just one example out of some: "Obtaining the the Change […]" (l. 12)

    3. The description of the numerical model is quite scarce despite the complexity of the model. Here you should add some more detail and precision, for example by using a numerical flow chart.

    4. Circular, square and triangle textures were studied. The triangles were further rotated. However, the geomerical parameters in terms of width, depth and lateral distance are kept constant. Therefore one must be very careful in the interpretation of the results and statements about the advantages of certain geometries. The proper way would be to first optimize the dimensions of the individual geometries for themselves and then compare their optima, see Etsion (Modeling of Surface texturing in hydrodynamic lubrication, Friction 2013 1(3), 195–209). In view of this, the paper should be revised.

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