Prediction of Horizontal Gas–Liquid Segregated Flow Regimes with an All Flow Regime Multifluid Model
Round 1
Reviewer 1 Report
In this manuscript, the generalized multiphase modeling approach has been further developed to predict the horizontal segregated flow regimes and the slug flow in a horizontal annulus. The simulations show some success. This paper, as a follow-up to the authors' previous study on GEMMA, is worthy of publication considering it shows us the additional capability of GEMMA, although the agreement of prediction with the original data is not 'great' as claimed by the authors. I have a few comments for the authors to address:
General comment:
1. A coordinate system is not defined for Fabre et al. experiment in this manuscript, but it's sometimes y is used. In figures like Figure3. there is also no coordinate system.
2. The authors claimed "a good agreement" somewhere, e.g. L355, L282. But for my understanding, a relative difference larger than 10% is not convincing as a good agreement.
Minor comments:
- L143-L144, it's better to specify for each term the symbol. e.g. drag (Fd)
- L182-L183, "Resolution is acceptable if higher than a critical value, as- 182 assumed in this work to be equal to 2." Why it's assumed to be 2? Is there any reasoning/evidence on choosing this value?
- L206, should be Eq.(11)
- L258, here 9.1 m is used. But at other places, 9 m is used. They should be consistent.
- L280, integrating should be replaced by averaging?
- L281-L282. I still saw the h perturbing. What will happen after 60 s?
- Figure 6 should be placed after L496 together with Figure 7
Author Response
We would like first to thank the reviewer for the useful comments that have helped us further improve the quality of the manuscript. Single comments are addressed one-by-one in the file attached.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this article, the authors further developed the GEMMA formulation for the application to horizontal and annular smooth and perturbed stratified flows. The manuscript is well written and organized. Some comments are:
1-Is there any other experimental database to be used by the authors? The only used reference seems to be the Fabre et al. study.
2-It would be very nice if the authors should provide discussion about flow physics. The focus seems to be on the comparison. However, any discussion about flow physics, which cannot be captured easily with experiments, will be helpful for the readers.
3-There are some deviations from the experimental results. More discussion and explanation about the trends in the differences will be helpful for the readers.
4-The authors should provide link to processes. The authors could provide guidelines about how their model will assist the researchers in having processes with better performances.
Author Response
We would like first to thank the reviewer for the useful comments that have helped us further improve the quality of the manuscript. Single comments are addressed one-by-one in the file attached.
Author Response File: Author Response.pdf
Reviewer 3 Report
I agree to the publication of this paper.
Author Response
We would like to thank the reviewer for the positive review of our manuscript.
Round 2
Reviewer 2 Report
The authors addressed most of the comments of the reviewer. The reviewer thanks them for careful revision.
