PONE-D-21-31025Crank Nicholson Scheme to Examine the Fractional-order Unsteady Nanofluid Flow of Free Convection of Viscous FluidsPLOS ONE

Dear Dr. Zubair,

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PONE-D-21-31025R1Crank Nicholson Scheme to Examine the Fractional-order Unsteady Nanofluid Flow of Free Convection of Viscous FluidsPLOS ONE

Dear Dr. Zubair,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Dec 09 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols.

We look forward to receiving your revised manuscript.

Kind regards,

Academic Editor

PLOS ONE

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Reviewers' comments:

Reviewer's Responses to Questions

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The manuscript presents the outcome of a research study on the fractional-order of unsteady

nanofluid flow due to free convection using Crank Nicholson integration scheme. The contribution of the report to the body of knowledge is significant and novel. Also, the aim and objectives of the study are within the scope of PLOS ONE. However, the present form of the report needs revision. The author should consider the following points:

Q1. The title is wrongly written. It was written, "Crank Nicholson Scheme to Examine the Fractional-order Unsteady

Nanofluid Flow of Free Convection of Viscous Fluids". Meanwhile, the report actually presents, "fractional-order of unsteady

nanofluid flow due to free convection using Crank Nicholson integration scheme"

Comment: Revise the title or consider, "Analysis of fractional-order of unsteady nanofluid flow due to free convection using Crank Nicholson integration scheme."

Q2. An effective Abstract is a global paragraph that prepares the reader for the rest of the document. The present form of the abstract is not acceptable because it is not appropriate.

Comment 1: Use

(1) one sentence to present the significance of the study,

(2) one sentence to present the aim of the study,

(3) one sentence to present the research methodology, and

(4) two sentences to present the conclusion drawn from the study.

Comment 2: Do not use the pronoun, "we" in a scientific report like this. Also, the first sentence of the abstract should focus on the significance of the study on, "Analysis of fractional-order of unsteady nanofluid flow due to free convection using Crank Nicholson integration scheme"

Q3. The present form of the introduction lacks structure and strongly rejected. It is important to release two comments which are

Comment 1: Writing is constructed by putting sentences in sequence, one after another. Meaning should flow from one sentence to the next, carrying the argument or point of view forward clearly and concisely.

Comment 2: Use the style mentioned above to revise not only the introduction section but also the analysis and discussion of results. This is necessary because some paragraphs are somehow scanty and not structure.

Comment 3:

After reading the introduction section, it is worth noticing that the present form of the theoretical and empirical reviews seems okay but not connecting related facts to open a gap which this report intends to fill.

Comment 4: Revise. The authors may check the following videos for insight: https://youtu.be/ugFJnflnsF0

https://youtu.be/1A27y6eUsqA

https://youtu.be/5GiT-N9Y_Ig

Q4. Revise the introduction. Update with scientific facts like:

Q4a) The manuscript lacks important facts on the choice of the value for Prandtl number.

Comment: Update the manuscript with the fact that "…the appropriate Prandtl number for (a) Methanol based nanofluid is 7.3786, (b) water-based nanofluid is 6.1723, (c) blood-based nanofluid is 22.9540, and Ethylene Glycol based nanofluid is 150.46."

Comment: Cite the Source - Physica Scripta 95(9), 095205. https://doi.org/10.1088/1402-4896/aba8c6

Q5. Update the discussion of the results illustrated as Fig. 13 and Fig. 14 with the fact that

a) An increase in the Grashof number or some other buoyancy-related parameter means an increase in the wall temperature, which weakens the bond(s) between the fluids, reduces internal friction pressure, and makes gravity stronger (i.e. makes the specific weight appreciably different between the immediate fluid layers adjacent to the wall).

You are expected to revise the fact above using your group of words.

Cite the source: Journal of Molecular Liquids 249, 980 – 990, 2018. https://doi.org/10.1016/j.molliq.2017.11.042

Q6. The analysis of the effect of Grashof number is not logical and insightful. Permit me to remind you of heating the surface and cooling the surface.

Comment: Do you know that there are three different implications of increasing Grashof number proportional to the buoyancy force? Could you try to extend your simulation to check what will happen to the transport phenomenon when (a) Grashof number is greater than 1, (b) Grashof number is less than 1, and (c) Grashof number is small like 0.01. Relate your observation(s) with the first conclusion (i.e. Velocity increases with increasing value of temperature-dependent viscosity parameter when Grashof number is greater than 1; velocity decreases with increasing values of temperature-dependent viscosity parameter when Grashof number is less than 1. The two effects exist when Grashof number is moderately small) reached in page 117 of Open Journal of Fluid Dynamics, 2015, 5, 106-120. http://dx.doi.org/10.4236/ojfd.2015.52013.

Q7. Section three is loaded with new results that are not clear. Nothing is known on the direction of thought. Research Questions are needed at the end of the introduction to harmonize the findings of the study.

Comment 1: The video below may be useful to guide the authors

https://youtu.be/cn4iRvtwf8M

Comment 2: The author should update the manuscript with appropriate and relevant research questions at the end of the introduction section. This would guide the author to structure a logical analysis of results. Logical questions are expected. This would help readers to link what is known in the literature with the novelty of this study. Samples of Research Questions can be found in the following reports

A. https://doi.org/10.1038/s41598-021-81417-y

B. https://doi.org/10.1007/s10973-021-10550-7

Reviewer #2: 

 <table border="0" class="datatable" id="ctlReviewQuestionsResponses_AnswersMatrix" style="border: 1px solid rgb(204, 204, 204); border-collapse: collapse; width: 1256.52px; line-height: 14px; color: rgb(0, 0, 51); font-family: verdana, geneva, arial, helvetica, sans-serif; font-size: 11.2px; background-color: rgb(244, 244, 244);"> 1. Write at least two sentences that highlights the practical application of this research.

2. Paper should be carefully revised for punctuation, grammar, space, and spelling mistakes. There are number of such kind of mistakes that must be tackled.

3. Nomenclature can help the readers to understand the number of variables used in the article. So add a nomenclature with the units.

4. Physical reasoning is missing in most of figures. Write in detail the true physical reason for increasing or decreasing.

5. The introduction section needs to be carefully revised. It is suggested that most related articles should be cited. The following articles can help you to improve your introduction section.

https://doi.org/10.1016/j.icheatmasstransfer.2021.105563

https://doi.org/10.1177/09544089211043605

https://doi.org/10.1002/htj.22280

https://doi.org/10.1002/htj.21947

https://doi.org/10.1007/s10973-020-09943-x

https://doi.org/10.1080/01430750.2020.1831593

https://doi.org/10.1038/s41598-020-61215-8

6. The abstract should be updated with fruitful outcomes of the problem.

7. All governing equations need to be referenced properly.

8. Some unclear words are used in the paper rectify it.(less...) </table>**********

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

Crank Nicholson Scheme to Examine the Fractional-order Unsteady Nanofluid Flow of Free Convection of Viscous Fluids

PONE-D-21-31025R2

Dear Dr. Zubair,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Naramgari Sandeep, Ph.D

Academic Editor

PLOS ONE

Reviewers' comments:

Reviewer's Responses to Questions

6. Review Comments to the Author

Reviewer #1: Checking through the revised version, it is worth mentioning that

a. the manuscript contains an interesting and novel aim,

b. the title is informative and relevant,

c. the introduction, literature review, methodology, results, discussion of results, conclusion and references are of high standard,

d. Author(s) have rigorously revised the manuscript. The present form of the whole report is also of high standard, and

e. the contribution of the report to the body of knowledge is significant.

Based on these aforementioned facts, it is worth concluding that the article is error free and suitable for publication. I hereby recommend "Acceptance".