Flow Regime, Slug Frequency and Wavelet Analysis of Air/Newtonian and Air/non-Newtonian Two-Phase Flow

Round 1

Reviewer 1 Report

In the paper under review, the authors study gas/Newtonian and gas/non-Newtonian two-phase horizontal fluid flow by analyzing their flow regime identification and flow structural analysis on the horizontal flow loop apparatus. The authors make extensive use of methods of the wavelet analysis. As far as I know, the results are original. I think these results provoke an interesting discussion among specialist engineers and theorists. Nevertheless, the manuscript is not without flaws. The following comments will help authors improve their work.
(1) The title of the article is not informative; it does not fully reflect the essence of the work.
(2) It is advisable to explicitly indicate the rheological models of the used materials.
(3) It is known that the use of wavelet analysis methods in many cases is effective, but at the same time it is often associated with serious computational difficulties. Authors should discuss this in detail in their work for the problems under consideration.
(4) A more detailed discussion of possible applications of the results of the work and its practical significance in various technologies is needed.

Author Response

Reviewers 1:

(1) The title of the article is not informative; it does not fully reflect the essence of the work.

The title of the article is modified in the revised manuscript, (line numbers 1-4).

(2) It is advisable to explicitly indicate the rheological models of the used materials.

The power-law model was used and values are included in Table 1 in the revised manuscript, (line numbers 127).

(3) It is known that the use of wavelet analysis methods in many cases is effective, but at the same time, it is often associated with serious computational difficulties. The authors should discuss this in detail in their work for the problems under consideration.

The details of the data input method for the I-D wavelet packet analysis is added in the revised manuscript, (line numbers 286-292).

(4) A more detailed discussion of possible applications of the results of the work and its practical significance in various technologies is needed.

Further importance of the practical significance is added in the revised manuscript, (line numbers 56-61, 97-99, 142-145, and 510-512).

Author Response File: Author Response.doc

Reviewer 2 Report

The authors are in a hurry to submit the paper containing many typos and grammatical errors.

Some notations such as $gd$ in many equations are not defined. 

The equations mentioned in lines between 227 and 229, and line 236 must be changed. 

Equation (15) is incorrect. 

Unclear statements: lines 328-329  Rewriting the sentences

                              lines 334-336  Rewriting the sentences

                              lines 356-357  Please describe the results from this comparison ;

                              line 361          Give an appropriate reason why the predicted data do                                                         not agree with experimental data; 

                              line 377          Airflow rate is never given in this study;

 Captions of various figures such as Fig 10, Fig13 and etc  need to be improved                    

 

Author Response

Reviewers 2:

(1) Some notations such as $gd$ in many equations are not defined.

The notations are updated in Appendix A of a revised manuscript, (line numbers 530).

 (2) The equations mentioned in lines between 227 and 229, and line 236 must be changed.

The above-mentioned equations numbers are updated in the revised manuscript, (line numbers 235, 237 241 and 242).

(3) Equation (15) is incorrect.

The Equation (15) is updated in the revised manuscript, (line numbers 240).

(4) Unclear statements: lines 328-329  Rewriting the sentences.

The sentences are updated in the revised manuscript, (line numbers 345-346).

(5) lines 334-336  Rewriting the sentences.

The sentences are updated in the revised manuscript, (line numbers 351-354).

 (6) lines 356-357  Please describe the results from this comparison.

Further importance of the practical significance is added in the revised manuscript, (line numbers 374-376).

(7) line 361 Give an appropriate reason why the predicted data do not agree with experimental data.

The specific reason is updated in the revised manuscript, (line numbers 379-380).

(8) line 377 Airflow rate is never given in this study.

The details of the Airflow rate are updated in Table 1of the revised manuscript, (line numbers 127).

 (9) Captions of various figures such as Fig 10, Fig13 and etc  need to be improved.

The captions of the suggested Figures are updated in the revised manuscript, (line numbers 347,362, 391, and 399).

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

I have carefully read the reply of the authors. They included the answers in the revised version of the manuscript. In general, the quality of the paper has been improved. I think that this paper can be recommended for publication. However, the prior check for English grammar is required (typos, technical terms, etc.), throughout the manuscript.

Author Response

I have carefully read the reply of the authors. They included the answers in the revised version of the manuscript. In general, the quality of the paper has been improved. I think that this paper can be recommended for publication. However, the prior check for the English grammar is required (typos, technical terms, etc.), throughout the manuscript.

The English grammar/proofreading of the revised manuscript is carrying out via MPDI’s editing service.

Author Response File: Author Response.doc

Reviewer 2 Report

In this manuscript, an experimental model of two-phase fluid flow through the loop apparatus with connected horizontal, vertical, and inclined test sections was set up to study the gas-flow behavior including flow pattern, slug frequency. However, this experiment was carried out the results only from the horizontal section and details of experiment conditions are not given, and refer to the conditions applied to study the rheological behavior of Xanthan gum solutions. Using MATLAB wavelet toolbox, flow analysis was carried out and compared with some existing results in the literature. There are some typo and grammatical errors , and also some mistakes in equation (12) and equation (15). The content of this manuscript seems to be interesting, it may be accepted after minor revision.

Author Response

In this manuscript, an experimental model of two-phase fluid flow through the loop apparatus with connected horizontal, vertical, and inclined test sections was set up to study the gas-flow behavior including flow pattern, slug frequency. However, this experiment was carried out the results only from the horizontal section and details of experiment conditions are not given, and refer to the conditions applied to study the rheological behavior of Xanthan gum solutions. Using MATLAB wavelet toolbox, flow analysis was carried out and compared with some existing results in the literature. There are some typo and grammatical errors, and also some mistakes in equation (12) and equation (15). The content of this manuscript seems to be interesting, it may be accepted after minor revision.

The detailed experimental procedure is reported in the experimental method section (2.2 Experimental methods), and parametric conditions are briefly summarized in Table 1 (line 134). The equations no. 12 and 15 are updated in the revised manuscript, line number, 222, and 240, respectively. Furthermore, The typo errors are removed throughout the revised manuscript, and the English grammar/proofreading of the revised paper is also carried out via MPDI’s editing service.

Author Response File: Author Response.doc