Vibration Characteristics of a Tubular Turbine Prototype at Different Heads with Considering Free Surface and Water Gravity
Round 1
Reviewer 1 Report
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Author Response
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Reviewer 2 Report
The paper describes characteristics of a vibration process in a turbine using a prototype, where the authors conducted some measurements to validate the simulation. However, some comments should be performed before its publication:
· To highlight the more relevant contribution of the current research with regard to previous publications.
· To conduct an analysis of mesh sensitivity in order to know hoe the number of cells can alter results.
· To include the governing equations for making the simulation. It is important to specify details of the used software.
· To verify citation along the text since in some parts there are references as “Literature [x]”. The authors should improve citations in lines 63, 72, and 132.
Author Response
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Reviewer 3 Report
This is a good study but written poorly. There are too many word-choice problems in the title and in the paragraph. Exaggerating terms are used frequently which should be avoided. Sentences are mostly non-English, and some are simply illogical. For example, runner is a solid part and a fluid can’t be “in” it; in CFD, reservoir area and runner area are only meaningful when discussing the boundary condition. Turbulent energy vorticity is a new term to the reviewer. Is it turbulent kinetic energy, dissipation rate, eddy viscosity, or something else?
Simulation model needs more in-depth discussion, especially how the vibrations are obtained. Are they abstracted from the Navier-Stokes solutions or from some other model? If from solving the Navier-Stokes equations, then what’s the "Delta t"? Parametric notations in the 1st paragraph on page 3 need to be labeled on geometric diagram.
In the result discussion, the authors need to provide the proof for every finding. Those include the cavitation, superposition of low pressure, fatigue damage, “condition 1 has a higher head and a smaller submergence depth for turbine”, etc. Also the Delta H has never been defined.
Author Response
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Round 2
Reviewer 1 Report
The authors fail to address many issues I raised with this paper. These points are very important because they hinder readers' understanding of the analyses. So I will reiterate the points that need further improvements:
1. The authors completely ignored the misused words or non-English expressions I listed in the previous report. Among them, the "turbulent energy vorticity", in particular, is a scientifically wrong terminology which no one has ever used (a simple Google search can reveal this). Therefore, no readers can comprehend what this means.
2. Regarding the title (point 1 of the original report), the authors' response only confirms that the "action of free surface" is misleading. The "action" strongly implies motions, and thus I suggest something like "Vibration Characteristics of Tubular Turbine Prototype at Different Heads Considering Free-Surface Levels and Hydro-Gravity Force"
3. Point 8 of the original report: Please include this in the paper.
4. Figure 11 (point 9 of the original report): the issue with figure 11 is that the 3D plots make it difficult to pin-point a specific frequency and compare across different locations. Moreover, the 3D plot use perspectives and not orthographic projections, which render it hard to compare the frequency magnitudes. Instead, the authors should select important frequencies discussed in section 3.2, and use line plots like figure 12 to show how the pressure at a frequency varies with locations.
5. Figure 12 (point 10 in the original report): I cannot find the definition of the "maximum amplitude" in the revised manuscript. Please include them in the paper. Moreover, please also include in the text or figure caption at what frequencies the maximum pressure fluctuation appear.
6. Section 3.2 (point 12 in the original report): The authors fail to make the connections more explicit. For example, the authors can mention in section 3.2 whether the variation of the pressure pulsation magnitude under different operating conditions agrees with the flow features in 3.1, or whether some frequencies are related to the features discussed in 3.1.
Author Response
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Reviewer 2 Report
Dear authors:
Please changed the word "Literature" by the surname of the authors in line 56.
Check the use of APA rules in all references.
Author Response
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Reviewer 3 Report
Although the authors had made a lot of improvement, added some important paragraphs, the writing issue still remain. The incorrectness can still be seen in punctuation, word spacing, citation, etc. For example, on line 62, Liu [18] should be Liu and Chane [18]; on line 7, Feng Jianiun[19] should be Feng et al.[19]; on line 71, Xu[20] should be Xu et al.[20]; on line 125, are different grids should be is the number of grids; on line 146, “…fluid ,kg/m^3” should be “…fluid, kg/m^3”; on line 148, N/m3 should be N/m^3; on line 160, the epsilon should not be on superscript location; on line 207, tubular and turbine should use single space; on line 234, “the volume of the eddy” should be replace with “the region of the eddy”. The reviewer believes there are still many mistakes not mentioned in this report.
Turbulent kinetic energy sometimes can be shortened as turbulent energy. Vorticity is defined as curl V, which represents the flow rotation. The reviewer had never seen these two terms are connected together. Maybe the authors can provide some references to explain what it is.
Author Response
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Round 3
Reviewer 1 Report
The revised manuscript has significantly improved, however the authors still fail to clearly explain the content of figure 7 (and use confusing words) after correcting the word "turbulent energy vorticity". Based on the revised figure, I guess the authors plotted the vortex structure using isosurfaces of vorticity or Q, and showed the strength of turbulent kinetic energy on the vortex structure. This CANNOT be shortened to "show the vortex distribution and the turbulent kinetic energy vortex" (line 228). Two things are shown in figure 7: one is the isosurface and the other is the TKE strength on the isosurface. Moreover, "TKE" and "vortex" should not be connected as one word. To make it clear, the authors should state explicitly what isosurfaces are plotted and what the contour color on the isosurfaces are in both line 228 and the caption of figure 7.
The "0.3" in the caption of figure 11(d) is missing and, instead, appears along side with the figure.
Author Response
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