Fluid-Structure Interaction Response of a Water Conveyance System with a Surge Chamber during Water Hammer

Round 1

Reviewer 1 Report

Please see the attached report for referee's comments.

Comments for author File: Comments.pdf

Author Response

The complete responses to reviews

Deep appreciation would be expressed to the editors and the anonymous reviewers for their helpful comments on our manuscript entitled “Fluid-Structure Interaction Response of a Water Conveyance System with a Surge Chamber during Water Hammer”(ID: No. water-733870 ). According to these comments and suggestions, the authors revised the MS carefully. 

Thanks for your time and effort in reviewing this MS. We also carefully revised the manuscript again, including grammar problems, type errors, English expression, and scientific contents. Please check the MS with track changes. The following are the necessarily responses for the comments in detail:

 

• Authors should provide key findings of reference 19 in the introduction section as thatstudy is being cited as a basis for the current research.

Zhang and Niao derived analytical formulas for the water level in surge chamber and dynamic pressure in pipe, it was the basis of this work. 

• Symbols shown in figure 2 should be fixed

As shown in figure 2 in MS, the symbols have fixed

• Authors did not provide few key details regarding their simulations:
• Did authors perform grid independence study to make sure their results are independent of grid size?

It is not clear whether authors used an inhouse solver or a commercial software.

We perform grid independence study in section 5, the results is shown in Fig.8. The numerical results of maximum pressure vary with is given in Fig.8. From Fig. 8, Δt=0.005 s and Δx=0.1 m are adopt.

All the numerical is obtained by a computing code written by the first author to perform complex matrix calculations 

• Line legend in figure 11 should be “First order” instead of “Frist order.

In Fig.10, First order” instead of “Frist order” have replaced by “First order” .

• Authors should carefully proofread the manuscript as there are a few typos and grammatical errors

We also carefully revised the manuscript again, including grammar problems, type errors, English expression, and scientific contents.See  the blue fonts in MS

• A uniform font size should be used in the whole manuscript. Currently, different font sizes are used in different places, for e.g., in Appendix.

We also carefully revised the manuscript again. manuscripthas been written with Palatino Linotype (10) but references, names of figures and names of tables (Palatino Linotype 9 ) 

Author Response File: Author Response.doc

Reviewer 2 Report

Water hammer has a great significance in the chemical installations (such as Refineries), power industries (Power plant stations) and civil systems (such as water supply). The term water hammer is commonly associated with accidents and fatalities. For some, the use of this term evokes images of broken and bent piping, the loss of water supplies to cities, and the deaths of individuals due to water hammer accidents. In the framework of this manuscript the authors have developed experimental system, conducted experiments and performed numerical calculations by applying Finite Volume Method. In my opinion this work can be further extended to evaluate the structural integrity of the pipe system by calculating the von misses stresses field of the pipe or the elbow and comparing to ultimate tensile stress and yield. Moderate English changes required. This manuscript should be accepted after performing major revisions.  

Comments and Suggestions for Authors

1) The abstract needs to include the main impact of this study. The novelty of this study should be strengthen and emphasized based on gaps of current literature.

2) The authors should discuss the significance of water hammer phenomena and its risks involved in the chemical installations (such as Refineries), power industries (Power plant stations) and civil systems (such as water supply). It is recommended to cite the following book:

[1] Robert A. Leishear, Ph.D., P. E., Fluid Mechanics, Water Hammer, Dynamic Stresses, and Piping Design, 2012, ASME, 3 Park Avenue, New York, NY 10016, USA (www.asme.org).

3) (Lines no. 90 - 93) Equations (1) - (4) should be referenced.

4) (Line no. 90) the term R_f term appearing in equation (1) should be defined. I have looked at several papers, this term is a function of the friction factor (see comment no. 7).

5) (Line no. 137) Figure 2 is blurred. The sketch of the elbow should be replaced with high resolution image.

6) (Line no. 159) there is a need to perform mesh dependency check, i.e. to present a graph or table which include the convergence of the solution as a function of the mesh size. If the Finite Volume Method (FVM) code has been already applied before, it should be referenced.

7) (Lines no. 202 - 215) the pipe material should be described.

8) (Lines no. 241 - 242) the authors should explain how, did they calculate spectral density. Did they perform Fast Fourier Transformation (FFT) on the experimental results?

9) (Line no. 247) the authors should address the pressure losses of the flow system (which include the pipe, elbow and the vessel exit). The pressure loss is calculated by using Darcy – Weisbach equation [1]:

                                   deltaP=f*L/D*rho*V^2/2

The definitions of the terms appearing in the above equations are shown in the pdf format. It should be noted that the friction factor (f) is a function of the surface roughness of the pipe, Reynolds number and the flow regime – laminar flow, transition zone and turbulent flow. These values should be shown and considered. It is recommended to present the values of Reynolds number. The following graph shows the friction factor as a function of Reynolds number and the flow regime (see the attached pdf format).

This diagram has been taken from the following web site:

[2] http://www.thermopedia.com/content/789/

10) (Line no. 257) the heading of section 5 should be moved to the following page.

11) (Line no. 263) in my opinion the phrase "1 m3/s" should be corrected to 1 m³/s.  

12) (Line no. 322) the sentence "In this paper, the water pipeline is in a plane, it is appropriate to decouple pipe motion out of plane." is not clear. It should be rewritten

13) The conclusion section should be extended. It should include the novelty and the main contribution of this study.

14) (Reference section Lines no. 359 -430) the publication year of the papers and the books should not appear in bold fonts. The authors should insert also the DOI of the papers. See the following reference example:

1. Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range, DOI.

 

Comments for author File: Comments.pdf

Author Response

The complete responses to reviews

Deep appreciation would be expressed to the editors and the anonymous reviewers for their helpful comments on our manuscript entitled “Fluid-Structure Interaction Response of a Water Conveyance System with a Surge Chamber during Water Hammer”(ID: No. water-733870 ). According to these comments and suggestions, the authors revised the MS carefully. 

Thanks for your time and effort in reviewing this MS. We also carefully revised the manuscript again, including grammar problems, type errors, English expression, and scientific contents. Please check the MS with track changes. The following are the necessarily responses for the comments in detail:

1 The abstract needs to include the main impact of this study. The novelty of this study should be strengthen and emphasized based on gaps of current literature.

“In existing literature, waterhammerinduced FSI is not considered, the results without FSI may be inaccurate” and “From these results, the transiliences induced by waterhammer-structure interaction, and they play important roles in the orifice of surge chamber.” emphasized the gaps of gaps of current literature and revealed main impact of this study, separately .

2 For numerical validation, the computational parameters should be provided.The authors should discuss the significance of water hammer phenomena and its risks involved in the chemical installations (such as Refineries), power industries (Power plant stations) and civil systems (such as water supply). It is recommended to cite the following book:

[1] Robert A. Leishear, Ph.D., P. E., Fluid Mechanics, Water Hammer, Dynamic Stresses, and Piping Design, 2012, ASME, 3 Park Avenue, New York, NY 10016, USA (www.asme.org).

“Fluid Mechanics, Water Hammer, Dynamic Stresses, and Piping Design” was referenced. See the section 1 of MS 

3 (Lines no. 90 - 93) should be referenced

According to Tijsseling and Vary [12], Equations (1) - (4) are obtained

4 (Line no. 90) the term Rf term appearing in equation (1) should be defined. I have looked at several papers, this term is a function of the friction factor 

Rf and Rt are fluid damp coefficient and structure damp coefficient, separately, Rf =f|V|/4R, Rt =Rf ρtAt/ρfAf. 

5 (Line no. 137) Figure 2 is blurred. The sketch of the elbow should be replaced with high resolution image.

A clear Figure 2 has replaced the blurred Figure 2. 

6 (Line no. 159) there is a need to perform mesh dependency check, i.e. to present a graph or table which include the convergence of the solution as a function of the mesh size. If the Finite Volume Method (FVM) code has been already applied before, it should be referenced

We have performed grid independence study in section 5, the results is shown in Fig.8. The numerical results of maximum pressure vary with is given in Fig.8. From Fig. 8, Δt=0.005 s and Δx=0.1 m are adopt. 

7 Lines no. 202 - 215) the pipe material should be described

The experimental pipe is PVC, and pipe in section 5 is steel they have explained in section 4 and section 5, separately.

8 (Lines no. 241 - 242) the authors should explain how, did they calculate spectral density. Did they perform Fast Fourier Transformation (FFT) on the experimental results?

The numerical results performed by Fast Fourier Transformation, spectral density was obtained. It has explained in section 4. 

9 (Line no. 247) the authors should address the pressure losses of the flow system (which include the pipe, elbow and the vessel exit). The pressure loss is calculated by using Darcy – Weisbach equation [1]:

deltaP=f*L/D*rho*V^2/2

The definitions of the terms appearing in the above equations are shown in the pdf format. It should be noted that the friction factor (f) is a function of the surface roughness of the pipe, Reynolds number and the flow regime – laminar flow, transition zone and turbulent flow. These values should be shown and considered. It is recommended to present the values of Reynolds number. The following graph shows the friction factor as a function of Reynolds number and the flow regime (see the attached pdf format).

This diagram has been taken from the following web site:

[2] http://www.thermopedia.com/content/789/

Rf and Rt are fluid damp coefficient and structure damp coefficient, separately, Rf =f|V|/4R, Rt =RfρtAt/ρfAf. In this study, f = F(Re), Re is Reynolds number. Here, Re=ρf |V|d /ν, v is Kinematic viscosity of liquid. According the definition of Reynolds number, Re vary with V in a transient process. When Re<2100, f= 16/Re, when 3000<Re<100000, f= 0.079/Re0.25 [25,26], 2300<Re<3000, f=0.06539exp(-(Re-3516)2/1248) [27]. 

10 (Line no. 257) the heading of section 5 should be moved to the following page

The heading of section 5 have moved to the following page

11 (Line no. 263) in my opinion the phrase "1 m3/s" should be corrected to 1 m³/s.

“1 m3/s” have corrected to “1 m³/s”.

12 the sentence "In this paper, the water pipeline is in a plane, it is appropriate to decouple pipe motion out of plane." is not clear. It should be rewritten

“In this paper, the water pipeline is in a plane, it is appropriate to decouple pipe motion out of plane.”have replaced by “In this study, the water pipeline is in a plane, it is appropriate the couplings in plane is decoupled with the couplings out of plane”. 

13 The conclusion section should be extended. It should include the novelty and the main contribution of this study.

The conclusion section have extended by “It is distinguished from the existing literatures about water water conveyance system with a surge chamber that this study taken the waterhammer-structure interaction into account.” and “From these results, firstly, local transiliences emerge in the numerical results of dynamic pressure may be induced by waterhammer-structure interaction, but is not induced by false hydraulic vibration; secondly, considering FSI, the numerical results are more authentic and the peak is larger, thus, they play important roles in the orifice of surge chamber.”

14 (Reference section Lines no. 359 -430) the publication year of the papers and the books should not appear in bold fonts. The authors should insert also the DOI of the papers. See the following reference example:

1.Author 1, A.B.; Author 2, C.D. Title of the article. Abbreviated Journal Name Year, Volume, page range, DOI.

We have modified the references, see as reference section

Author Response File: Author Response.doc

Round 2

Reviewer 1 Report

Authors have addressed my comments and the manuscript in the present form can be accepted for publication.

Reviewer 2 Report

Dear authors,

Thank you very much for the work you have done. The article has been significantly improved. This manuscript should be accepted after performing minor revisions. The years appearing in the reference list should be bold (line no. 408, 422, 424, 426, 428 & 430). The title of section 5 (line no. 256) should be moved to following page.