Research on Energy Loss Characteristics of Pump-Turbine during Abnormal Shutdown
Round 1
Reviewer 1 Report
I can support the article for publishing in present form.
Author Response
Dear reviewer, thank you very much for your recognition of our article. We will make further efforts on this basis and do more in-depth research.
Reviewer 2 Report
General review
The paper is very good because it focuses on a particular engineering problem. It is suitable for publishing with exactly one minor correction given below.
Correction
1.
Please provide a table that clearly defines the quantities that are in the input date set and the quantities that are calculated. This description may be placed in the section 2.4 of the paper that does not exist at the moment of the review but should be considered.
Specific comments
1.
Since the Authors used the UG NX software, it is not necessary to write the continuity equation (1) and the Reynolds equation (2). The software uses these equations in a different form than the general form provided by the Authors. It is applied to finite elements or to a differentiate scheme. So, it is sufficient to note that a particular software was applied.
2.
The equations (3) and (4) may be exchanged with the information about the settings that were used in the CFD software. Again, the general equations are ok, but the software uses them in a more practical way, which is a different than the theoretical approach. There is no shame in providing the software settings instead of the general equations.
Author Response
Dear reviewer，
Thank you for your comments on our article. We have responded to your comments and revised the article. Our reply is attached below for your convenience.
Sincerely, Yuxuan Deng BaiLie School of Petroleum Engineering, Lanzhou City University Telephone:+8615908150884 [email protected]Author Response File: 
Author Response.docx
Reviewer 3 Report
This study assessed the energy loss characteristics of pump-turbine during abnormal shutdown. Given that energy is a global concern, this paper is timely and could offer new insights on energy loss characteristics of pump-turbine during abnormal shutdown. The manuscript is generally well written and easy to understand. I suggest that the authors should revise the manuscript incorporating the following comments and suggestions into an updated version.
1. Use some statistical indicators (like coefficient of determination etc.) to assess the closeness of simulated and experimental values as shown on Figure 4.
2. On what basis the authors selected three working conditions of the pump to assess energy loss characteristics.
3. Why the authors selected entropy production theory and vortex dynamics to assess the energy loss characteristics in the current study.
4. How the selected techniques overweigh the traditional methods of hydraulic loss analysis?
5. On what basis the authors selected the main design parameters listed in Table 1.
6. On what basis the authors selected 8.4 million grid nodes for numerical calculation? In the Figure 3 the head becomes parallel and then start increasing.
7. On what basis the authors selected nine working points in three working areas for numerical simulation as shown on Figure 4 as there is big variability in between the selected points.
8. Why the entropy and vertex of the runner and double row cascade increases in the break and turbine condition in comparison to the other two as demonstrated by Figure 5. Explain it in the corresponding section.
Author Response
Dear reviewer，
Thank you for your comments on our article. We have responded to your comments and revised the article. Our reply is attached below for your convenience.
Sincerely,
Yuxuan Deng
BaiLie School of Petroleum Engineering, Lanzhou City University Telephone:+8615908150884
Author Response File: Author Response.docx
