Precise Evaluation of Gas–Liquid Two-Phase Flow Pattern in a Narrow Rectangular Channel with Stereology Method

Round 1

Reviewer 1 Report

This paper presents a study of the precise determination of two phase flow pattern based on stereological parameters analysis. The obtained results are shown against the flow map proposed by Mishima and Ishii. The experiment was taken in the thin clear channel with dimensions of W=50 × H=1200 × T=5 mm.

The paper’s subject is very practical and useful for measuring two-phase flow physical characteristics. The research procedure has been logically carried out. Therefore, I highly recommend this paper for publication in this journal but before that, I have some few comments on the text that should be addressed before publication:

 

Comments:

1)There are some typo errors in the text that should be corrected. For example, sentence in line 14: “…on stereological parameters analysis .” should be in this way “on stereological parameters analysis.” Please correct all the typo errors in text.

2)Quality of Figures 1, 2, 8 and 9 are too bad. Please replace them with a higher quality figure.

3)Is the proposed method in this study applicable to gas-oil-water three phase flows?

4) I highly recommend the authors to add some references in manuscript about other techniques used for measuring two-phase flow characteristics. I recommend the others to add all the following references, which are the newest references in this field. In fact, the references refer to the most typical techniques (electrical capacitance [1-2], gamma radiation [3], X-ray attenuation [4] and ultrasound [5]) for determining void fraction and flow regime in two-phase flows.

[1] Almutairi, Z., Al-Alweet, F.M., Alghamdi, Y.A., Almisned, O.A. and Alothman, O.Y., 2020. Investigating the characteristics of two-phase flow using electrical capacitance tomography (ECT) for three pipe orientations. Processes, 8(1), p.51.

[2] Xu, Z., Wu, F., Yang, X. and Li, Y., 2020. Measurement of gas-oil two-phase flow patterns by using CNN algorithm based on dual ECT sensors with venturi tube. Sensors, 20(4), p.1200.

[3] Evaluation of flow pattern recognition and void fraction measurement in two phase flow independent of oil pipeline’s scale layer thickness. Alexandria Engineering Journal, doi.org/10.1016/j.aej.2020.11.043

[4] Combination of X-ray tube and GMDH neural network as a nondestructive and potential technique for measuring characteristics of gas-oil–water three phase flows. Measurement, 168, p.108427. doi.org/10.1016/j.measurement.2020.108427

[5] Fang, L., Zeng, Q., Wang, F., Faraj, Y., Zhao, Y., Lang, Y. and Wei, Z., 2020. Identification of two-phase flow regime using ultrasonic phased array. Flow Measurement and Instrumentation, 72, p.101726.

Author Response

REVIEWER 1 comments and answers:  

 

This paper presents a study of the precise determination of two phase flow pattern based on stereological parameters analysis. The obtained results are shown against the flow map proposed by Mishima and Ishii. The experiment was taken in the thin clear channel with dimensions of W=50 × H=1200 × T=5 mm.

The paper’s subject is very practical and useful for measuring two-phase flow physical characteristics. The research procedure has been logically carried out. Therefore, I highly recommend this paper for publication in this journal but before that, I have some few comments on the text that should be addressed before publication:

Thank the reviewer for the favourable recommendation, indicating the usefulness of the research conducted. The article has been revised as suggested. All changes made can be easily tracked on the attached additional file.

Comments:

1) There are some typo errors in the text that should be corrected. For example, sentence in line 14: “…on stereological parameters analysis .” should be in this way “on stereological parameters analysis.” Please correct all the typo errors in text.

Thank you for your careful reading and for pointing out errors. The article has been thoroughly checked and all errors noted have been corrected.

2) Quality of Figures 1, 2, 8 and 9 are too bad. Please replace them with a higher quality figure.

The figures were prepared in better quality.

3) Is the proposed method in this study applicable to gas-oil-water three phase flows?

Yes, a requirement for the use of stereological methods to evaluate the structure of a gas-oil-water mixture is to make visualizations that allow the distinction of each phase. Making images, in this case, can be done by any technique: bright field technique, laser knife, ultrasonography, X-ray, etc.

4) I highly recommend the authors to add some references in manuscript about other techniques used for measuring two-phase flow characteristics. I recommend the others to add all the following references, which are the newest references in this field. In fact, the references refer to the most typical techniques (electrical capacitance [1-2], gamma radiation [3], X-ray attenuation [4] and ultrasound [5]) for determining void fraction and flow regime in two-phase flows.

[1] Almutairi, Z., Al-Alweet, F.M., Alghamdi, Y.A., Almisned, O.A. and Alothman, O.Y., 2020. Investigating the characteristics of two-phase flow using electrical capacitance tomography (ECT) for three pipe orientations. Processes, 8(1), p.51.

[2] Xu, Z., Wu, F., Yang, X. and Li, Y., 2020. Measurement of gas-oil two-phase flow patterns by using CNN algorithm based on dual ECT sensors with venturi tube. Sensors, 20(4), p.1200.

[3] Evaluation of flow pattern recognition and void fraction measurement in two phase flow independent of oil pipeline’s scale layer thickness. Alexandria Engineering Journal, doi.org/10.1016/j.aej.2020.11.043

[4] Combination of X-ray tube and GMDH neural network as a nondestructive and potential technique for measuring characteristics of gas-oil–water three phase flows. Measurement, 168, p.108427. doi.org/10.1016/j.measurement.2020.108427

[5] Fang, L., Zeng, Q., Wang, F., Faraj, Y., Zhao, Y., Lang, Y. and Wei, Z., 2020. Identification of two-phase flow regime using ultrasonic phased array. Flow Measurement and Instrumentation, 72, p.101726.

Thank you for pointing out the new literature. The suggestions were implemented and the text was supplemented with the suggested items. The text was also expanded with more new literature, which significantly enriched the paper.

Reviewer 2 Report

The paper presents an interesting study of two-phase flows by stereology means. I believe this paper is a good work, but a few changes must be done before publishing.

• It should clearly state what the contribution of the work is. This can be done in the introduction section, and then revisited in the conclusions section.
• The importance/relevance of the five stereological parameters should be explained. Why were these parameters chosen? What do they represent? 
• The results need further explanation. The authors have presented good introductory material, but the analysis of the results is insufficient. 
• Similarly, the conclusions section presents two key figures (Figs 8 and 9) which should be part of the results section, and which should be explained in more detail. Fig. 8 and 9 seems to present the main contribution of this work.

 

 

Author Response

REVIEWER 2 comments and answers:  

 

The paper presents an interesting study of two-phase flows by stereology means. I believe this paper is a good work, but a few changes must be done before publishing.

Thank the reviewer for the favourable recommendation, indicating the usefulness of the research conducted. The article has been revised as suggested. All changes made can be easily tracked on the attached additional file.

It should clearly state what the contribution of the work is. This can be done in the introduction section, and then revisited in the conclusions section.

The relevant sections of the article were completed with the following information. With the experimental results in this paper, an attempt is made to prove an earlier hypothesis, which stated that the parameters of a gas-liquid two-phase flow pattern can be accurately measured through stereology. The contribution of this work is the evaluation of the two-phase flow pattern, which allows for a more accurate description of the flow regime and makes it possible to quantitatively measure the characteristics of the flow structure.

The importance/relevance of the five stereological parameters should be explained. Why were these parameters chosen? What do they represent?

The basic and most important, from the process point of view, flow parameters of multiphase mixtures are phase fractions and the size of the interfacial surface. Reaching accurate values of these parameters was the basic aim of stereological parameters selection. Among many stereological parameters, the chosen ones allowed us to reach the goal as quickly as possible. A more detailed description of what each parameter represents has been added to the text.

The results need further explanation. The authors have presented good introductory material, but the analysis of the results is insufficient. Similarly, the conclusions section presents two key figures (Figs 8 and 9) which should be part of the results section, and which should be explained in more detail. Fig. 8 and 9 seems to present the main contribution of this work.

Thank you for this comment. Indeed, this arrangement can be confusing, so using the reviewer's suggestion we have reworded the text by moving relevant paragraphs and supplementing the text with a deeper discussion of the results.

Reviewer 3 Report

Reviewer Comments for the article named “New experimental measurement method for estimation of two-phase gas – liquid flow pattern in narrow rectangular channel with the use of stereology”

 

This paper proposes an image-based analysis for enabling the precise determination of two phase flow pattern using stereological parameter analysis. The abstract is written in poor English. While it does explain the content of the paper, the presentation can be made much clearer and precise. Also, please highlight what problem you are solving, why it needs a new approach to address, and how you are addressing it through your method.

 

Comments

1. The paper is well-structured in general. However, the value proposition and novelty, while present, is not highlighted and remains somewhat unclear.
2. Please provide sufficient detail in the second to last paragraph of the introduction section to highlight the novelty of the work while placing it in the context of the state-of-the-art.
3. Please change all the graphics as they are of poor quality and generally illegible.
4. The whole paper needs re-writing as it contains several grammatically incorrect sentences.
5. The results section only reports the findings and does not explain the differences between the authors’ method and the benchmark that they are comparing against. Explain the differences and the potential reason for the differences.

Author Response

REVIEWER 3 comments and answers:  

 

This paper proposes an image-based analysis for enabling the precise determination of two phase flow pattern using stereological parameter analysis. The abstract is written in poor English. While it does explain the content of the paper, the presentation can be made much clearer and precise. Also, please highlight what problem you are solving, why it needs a new approach to address, and how you are addressing it through your method.

Thank you for all your comments. The ambiguities have been resolved and the overall text has been significantly improved as suggested by the reviewer. All changes made can be easily tracked on the attached additional file.

Comments

1. The paper is well-structured in general. However, the value proposition and novelty, while present, is not highlighted and remains somewhat unclear.

Thank you for your attention. Novelty references have been introduced into the text. This is particularly pointed out in Section 3.

2. Please provide sufficient detail in the second to last paragraph of the introduction section to highlight the novelty of the work while placing it in the context of the state-of-the-art.

The entire article has been significantly supplemented with context.

3. Please change all the graphics as they are of poor quality and generally illegible.

The figures are prepared in better quality.

4. The whole paper needs re-writing as it contains several grammatically incorrect sentences.

The article has been thoroughly checked and any errors noted have been corrected.

5. The results section only reports the findings and does not explain the differences between the authors’ method and the benchmark that they are comparing against. Explain the differences and the potential reason for the differences.

The results are discussed in more detail.

Reviewer 4 Report

The authors have used the stereological technique to identify the flow region of a gas-liquid flow. The work is interesting and has a good potential for flow regime identification in two-phase flows. However, I  have the following main comments. 

• The introduction to the existing techniques of two-phase flow measurement is not complete. Inclusion of the pros and cons of the existing methods, and a description of the motivation behind the selection of stereology would add more value. More importantly, stereology has been used for two-phase flow identification by the same authors before, therefore clearly mention what the novelty in this work is. 
• the title is vague, not representative of the study, and gives a wrong impression.  
• The tests are done only for the bubble region, the addition of a discussion of how the performance would be for other regions would be interesting.   

some minor comments: 

figure 1 caption is not clear. 

some references are duplicated. 

 

Author Response

REVIEWER 4 comments and answers:  

 

The authors have used the stereological technique to identify the flow region of a gas-liquid flow. The work is interesting and has a good potential for flow regime identification in two-phase flows. However, I  have the following main comments.

Thank the reviewer for the favourable recommendation, indicating the usefulness of the research conducted. The article has been revised as suggested. All changes made can be easily tracked on the attached additional file.

The introduction to the existing techniques of two-phase flow measurement is not complete. Inclusion of the pros and cons of the existing methods, and a description of the motivation behind the selection of stereology would add more value. More importantly, stereology has been used for two-phase flow identification by the same authors before, therefore clearly mention what the novelty in this work is.

Thank you for pointing out the problems. All reviewer comments have been addressed in the revised manuscript. Novelty references have been introduced into the text. This has been particularly emphasized in Section 3.

the title is vague, not representative of the study, and gives a wrong impression. 

Thank you for pointing out the inaccuracy of the title. Indeed, in this paper, we describe not so much the method itself but the evaluation of flow patterns within a specific area on the flow map using the developed method. We are discussing the diversity of structural properties although they are considered unchangeable in particular areas. As suggested, the title has been changed to the following:

Precise evaluation of gas-liquid two-phase flow pattern in a narrow rectangular channel with stereology method

The tests are done only for the bubble region, the addition of a discussion of how the performance would be for other regions would be interesting.  

Correct, the study performed covered the bubble regime region. The analysis of transitions between flow regimes is still under intensive study. As soon as we refine the method for flow regime recognition the results will be published.

some minor comments: figure 1 caption is not clear. some references are duplicated.

Figures are corrected and duplicate references are removed.

Round 2

Reviewer 1 Report

All the comments have been addressed correctly and the paper is ready for publication.

Author Response

Dear Reviewer,

We thank you and all the reviewers for providing useful comments and feedback that were very helpful in improving this manuscript.  All reviewers believed that the paper contains material that is worthy of investigation and publication in your journal.  We are grateful for the opportunity to resubmit a revised manuscript according to your comments.

Because this review did not include comments we do not include the revised manuscript.

Thanking you again, we hope that this revised manuscript covers all the issues and answers all the concerns of the reviewers and we are appreciative of their thoughts and work. We believe that the revised manuscript is now much improved.

Sincerely,

Authors

Reviewer 3 Report

The graphics must be improved. The authors have sufficiently improved the quality of exposition in the paper and have addressed the comments.

Author Response

Dear Reviewer,

We thank you and all the reviewers for providing useful comments and feedback that were very helpful in improving this manuscript.  All reviewers agreed that the paper contains material that is worth investigating and publishing in your journal.  We are grateful for the opportunity to resubmit a revised manuscript according to your comments.

Since this review contained only comments on improving the quality of the graphics we are attaching a revised manuscript containing only the corrected graphics. In addition, we attach all corrected graphics as separate files so that an editor can use them.

Again, thank you, we hope that this revised manuscript covers all issues and addresses all concerns of the reviewers and we are grateful for their thoughts and work. We believe that the revised manuscript is now greatly improved.

Sincerely,

Authors

Reviewer 4 Report

the authors have addressed all my comments. 

Author Response

Dear Reviewer,

We thank you and all the reviewers for providing useful comments and feedback that were very helpful in improving this manuscript.  All reviewers believed that the paper contains material that is worthy of investigation and publication in your journal.  We are grateful for the opportunity to resubmit a revised manuscript according to your comments.

Because this review did not include comments we do not include the revised manuscript.

Thanking you again, we hope that this revised manuscript covers all the issues and answers all the concerns of the reviewers and we are appreciative of their thoughts and work. We believe that the revised manuscript is now significantly improved.

Sincerely,

Authors

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.