Three-Dimensional Analysis of Air-Admission Orifices in Pipelines during Hydraulic Drainage Events

Round 1

Reviewer 1 Report

The authors implemented a three-dimensional computational fluid dynamics model to a single pipe to analyze the effects of air inflow on the orifice installed at the pipe end. The authors showed good match between the model results and the experiment measurements. Can the authors add more description on how they set up the experiment to obtain the observations? Can the authors provide more details of  three-dimensional model parameters and how sensitive the model results are to these parameters?

Author Response

Hello editor

The authors would like to thank you for your efforts to promote the quality of the article. The comments were carefully read and all applied changes can be tracked in the revised manuscript. In addition, each comment has been responded to independently. We thank you again for your appreciation of this research.

 

Best Regards

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript “3D analysis of air admission orifices in pipelines during hydraulic drainage events” discusses about e effects of air inflow on an orifice installed in a single pipe during drainage events are analysed using a three-dimensional computational fluid dynamics model by testing orifices with diameters of 1.5 mm and 3.0 mm. This three-dimensional model was validated with different experimental measurements obtaining good fits. Additionally, the aerodynamic effects that occur during the air admission processes are studied, and the influence of the sizing of these orifices in the effective control of drainage processes. I have following comments for further improvement:  

·       The abstract should have quantitative outcomes of the study.

·       The first section should be aligned with global cause like SDGs/net zero.

·        The literature review part may be enhanced by adding studies 10.3390/pr9111867, 10.1016/j.applthermaleng.2022.118633, 10.1016/j.ijhydene.2022.04.152

·       Novelty of the study should be highlighted in abstract, Introduction, and conclusion.

·       Ensure all symbols and abbreviations are included in the list of nomenclature.

·       The equations used in section 3.1 should be cited properly.

·       Was mesh independence study carried out?

·       How the uncertainty in model analysed.

·       Why the RMSE value for Test 1 so high in table 3.  

·       The graphs shown in Figure 3 are not clear.

·       Quantitative results should be presented in conclusion.

·       Include future scope of the study.

 

It is well written and compact article. It may be considered after major revision.

 

Author Response

Hello editor

The authors would like to thank you for your efforts to promote the quality of the article. The comments were carefully read and all applied changes can be tracked in the revised manuscript. In addition, each comment has been responded to independently. We thank you again for your appreciation of this research.

 

Best Regards

Author Response File: Author Response.pdf

Reviewer 3 Report

In this paper, a three-dimensional numerical model was used to investigate the dynamic behavior of air admission orifices in pipelines during hydraulic drainage events. The aerodynamic effects that occur during the air admission processes are studied, and the influence of the sizing of these orifices in the effective control of drainage processes. I have some suggestions and comments before the paper can be accepted.

1.     The mesh independence has not been mentioned in the paper. Please describe the effect of mesh cell numbers on the accuracy of the results.

2.     Why do you combine with the energy equation? I don’t think it needs to calculate temperature. In addition, there is no temperature results provided. It only costs computational time to calculate temperature.

3.     Table 2 can be deleted. The initial values at boundaries are already mentioned in the text.

4.     The captions of Table 3 and Table 4 should be on the top of the table. Please ckech all similar mistakes.

5.     In Figure 4a, it looks like the differences between experiments and numerical simulations become larger after flowrate is larger than 0.6 m3/h. Why is that? It needs to provide some explanations.

6.     How do you know the streamlines in Figures 5 and 6 are reasonable? There is no comparison.

7.     Please proofread the entire manuscript carefully. Some sentences need to be condensed. For example, the sentence from Lines 1 to 3 can be condensed.  

8.     3.3 should be “numerical scheme”.

Author Response

Hello editor

The authors would like to thank you for your efforts to promote the quality of the article. The comments were carefully read and all applied changes can be tracked in the revised manuscript. In addition, each comment has been responded to independently. We thank you again for your appreciation of this research.

 

Best Regards

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have done well in revising the manuscript. It may be accepted. 

Reviewer 3 Report

I am sastified with thr authors' responses. I do not have further questions.