Influence of Guide Vane Profile Change on Draft Tube Flow Characteristics of Water Pump Turbine
N. Manzanares Filho
Round 1
Reviewer 1 Report
The paper presents a computational and experimental investigation on the influence of the change of the guide vane wing shape on the flow characteristics of the tail pipe (draft tube) of a reversible hydraulic turbine.
In the opinion of this reviewer, the article is of interest to the hydropower community and deserves attention for publication. Some minor points should, however, be considered by the authors in order to improve the manuscript.
1) Unless special argumentation, there are some unusual nomenclature that may be conveniently changed: “tailpipe/tail pipe” à “draft tube”; “worm shell” à “spiral casing”; “radius of the head circle” à "leading edge curvature radius".
2) Line 13: Subject and/or verb are missing from the sentence: “Reduced turbulent energy and improved tailpipe energy recovery”.
3) Line 31: “to try to make” à “in order to make”.
4) Line 60: acronym DT means “draft tube”. Please clarify.
5) Line 64: “. such downstream per turbations” à “. Such downstream perturbations”.
6) Line 79: What is the meaning of acronym MRF? Please clarify.
7) Lines 87-91: This last sentence is duplicated.
8) What was the procedure used for modifying the guide vane wing (Fig. 1b and Table 1)?
9) Line 103: “RImprove the geometry of …”. There is an error here. Please correct.
10) Line 115: The term “blade inlet placement angle” is duplicated; “is equal” à “are equal”.
11) Lines 115-116: What is the meaning of the unusual term “no deliquescence” in the intended context? Would it be the so called “shockless inlet condition”? Please clarify.
12) Line 140: What do the authors mean by the term “flow rate in the runner area …”. Would it be “fluid velocity” instead of “flow rate”? Please clarify.
13) What CFD software was used? ANSYS Fluent, ANSYS CFX or other one? Please specify.
14) Line 174: First appearance of “a0=33mm”. What is its meaning? Please clarify.
15) Lines 197-198: The expression “and the given probability range beyond the probability range will be ignored” is confusing. Please rewrite for clarity.
16) Table 5: It is important to define the “rated operating conditions” and the “Partial working condition operation”. What is the meaning of “Movable guide vane - between runners”? There is only one runner, right?
17) Figure 8: What is the meaning of “Hp”?
18) Figure 9 and Line 220: What is the meaning of T in the equality t5=T? Is it the time period for a complete runner revolution? Please clarify.
19) Line 220: The term “and it was found that the vortex was found…” is somewhat confusing. Please clarify.
20) Lines 234-235: Please rewrite the phrase “Overall, the modified guide vane will make the reversible hydraulic turbine tail pipe pressure pulsation, vibration noise exists to a certain extent to reduce”. The text is not very clear.
21) Figure 10: The term “tailpipe of the wing” seems incorrect.
22) Lines 237-238: “The figure” à “Figure 10”; what is the meaning of “non- constant conditions”? Please clarify.
23) Line 265: “The figure” à “Figure 11”.
24) What is the meaning of Δh_w and θ in Eqs. (3) and (4)?
25) Figure 12: Are monitoring positions d1, d2, d3, d4 associated with Plane-1 and d5, d6, d7, d8 associated with Plane-3-4? If so, please make it clearer. If not, make it clear what the actual association is.
26) Figure 13: Figures e-f-g-h are "frequency domain curves", not “time domain curves”.
27) Line 311: The term “1 The image curve” is confusing. Do authors mean Figure 13(e), the frequency domain curve for monitoring position d1?
28) Line 312 and Figures 13(e-h): What is the definition of Cp?
29) Line 314: “5 main frequency”. Do authors refer to the main frequency in the monitoring position d5?
30) Lines 320-322: The text “the complex state of water flow inside the tailpipe under low flow conditions, the interaction of vortex bands and backflow in the straight cone section, the bent elbow section and the diffusion section” looks disconnected from the rest of the paragraph.
31) Line 333-334: “Less swirling in the elbow section and diffusion section”. A verb is apparently missing from this text.
32) Line 344: “analysing” à “making”.
33) Line 346: “but reduces” à “but the modification reduces”.
Author Response
Many thanks to the experts for their valuable comments on this thesis, and the corresponding changes have been made based on the experts' comments.
Author Response File: 
Author Response.docx
Reviewer 2 Report
General comments:
1.I appreciate the simulation skills and work, but the results are given in a scattered manner. Further discussion has to make a coherent connection among the results.
2. Abstract. Give some quantified results and avoid general syntagma like "to a certain extent".
3.The paper should be English revised.
4.The Conclusions section should be revised, as the statements are too vague and general. I suggest to introduce some quantification.
Specific suggestions:
row13: The sentence "Reduced turbulent energy and improved tailpipe energy recovery." has no predicate.
row19: Explain the China's commitments regarding carbon dioxide.
row 43: The correct name is Iliescu, not Lliescu.
row 44: Explain what PIV stands for.
row 60: explain what DT stands for.
rows 64-66: check and correct all the phrase that starts with "such downstream per turbations can be..."
rows 72-73: check and correct "the unit is affected by the vortex will also have a decisive effect on the stability..."
row 79: Explain what MRF stands for.
rows 83-91: The same phrase is written twice.
row 103: correct the word "RImprove".
row 106: Refer to "Table 1" instead of "the table below".
row 109: Give the significance and unit measure for the amounts in the two relationships.
row 115: "blade inlet placement angle" is repeated twice.
page 6: give the nomenclature and unit measure for the relationships (1) and (2).
Figure 8: Correct the syntagma "simulate curves" in the legend.
row 183: "the error value is kept within 6%, which meets the requirements of engineering research". Please cite the document that stipulates this requirement.
row 189: It is mentioned a cavitation number. Please specify it!
row 191: It is written "The sensor arrangement should be located where the maximum pressure pulsation amplitude can be measured." Say where!
row 197: I didn't understand the syntagma "The characteristic amplitude uses the statistical out and the given probability range beyond the probability range will be ignored"
row 202: It is written "the test results are shown in Table". Write the table number!
Table 4: What does it mean " Monitor the location"? I thing it is about the monitoring location.
Table 4: In the first two rows is mentioned " the spinal canal ". Is it for real?
Table 5, First row, first column: " Worm shell import". What does it mean?
Figure 9: Lacks in explanation, especially for dt1, dt2.... The figure spans on two pages. The reference frame is too small to be read.
row 217 and 220: explain "the moment t5=T"
row 227: I didn't understand the syntagma "smoothly continue to continue to pass downward".
row 234: I didn't understand the syntagma ". Overall, the modified guide vane will make the reversible hydraulic turbine tail pipe pressure pulsation, vibration noise exists to a certain extent to reduce." Please rephrase!
row 237: Specify the number of the figure, like The Figure 10 shows...
Figure 10: Place the whole figure and its caption on the same page. There are indicated some magnified spots but I don't see all of them.
row 251: It is written "...causing the intermediate velocity to be lower than the wall" Please correct! You can't compare a velocity to a wall.
row 265: Specify the number of the figure. It should be "The Figure 11 shows..."
Page 12: Give the nomenclature and unit measure for all the notations in the relationships (3)-(6).
row 291: the velocity v1 doesn't occur in any of the relationships (3)-(6).
Figure 12: Make the connection between the tailpipe and the cross sections where the monitoring spots are marked.
row 311: I didn't understand the phrase "1 The image curve has a dominant frequency..."
row 314: I didn't understand the syntagma " ...5 main frequency 314 of 6.04 Hz is about 0.25 times the rotation frequency..."
row 323: It is written "...increases the threshold of stable operation of the reversible turbine to a certain extent." Please specify the extend. It is too vague.
Section Conclusions has to be revised. I suggest a more carefully editing and a more rigorous formulation.
References
row 380: instead of "Cioncan G D" write " Ciocan G D".
Author Response
Many thanks to the experts for their valuable comments on this thesis, and the corresponding changes have been made based on the experts' comments.
Author Response File: Author Response.docx
Reviewer 3 Report
Manuscript
Title: „Influence of Guide Vane Profile Change on Tailpipe Flow Characteristics of Water Pump Turbine”
Authors: LI Qifei, Lu XIN, Gengda XIE, Siqi LIU, Qifan Wang
Dear Authors
I revised the manuscript: "Influence of Guide Vane Profile Change on Tailpipe Flow Characteristics of Water Pump Turbine" submitted to the “Processes” Journal. The paper is very interesting. However, I have some concerns, which need to be addressed.
Line 2-3. Article topic
The formulation of the article's topic is detailed and strictly indicates the coincidence of parameter values and system response.
Abstract:
The abstract is extremely concise in terms of describing the key elements of the research paper. However, the lack of documentation of the results in terms of numerical values of key parameters is not wrong. However, I believe that the lack of presentation of numerical values for the key parameters of the analysed system indicates that the authors had trouble to identify and adequately summarise their own results. Please consider increasing the information in terms of the key research method and key parameter values to confirm the correctness of the conclusions.
Keywords. „Vane Profile Change” Keywords are chosen correctly. I believe that there is a lack of relatively precise reference to the forcing element in the form of the „lead vane profile”. Please consider introducing this element into the keywords.
1. Introduction
Line 19-91.The introduction logically reveals the state of scientific knowledge on the presented topic. The authors have clearly outlined the research goal of the paper. The introduction prepares the reader well for reading the further chapters of the work.
The numbering of literature sources in the text is in accordance with formal requirements. The content of the chapter introduces the reader to the problematic issue in a logical and understandable way.
Line 21, 24, 32, 40, 43, 50, 53, 60, 62, 64, 68, 71, „….country[1]. ….”
Line Please remember to put a space between the sentence content and the literature source, for example "....country [1]. ...."
Line 44. „…PIV…” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 54. „….CFD….” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 60. „….DT…..” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 79. „….MRF…..” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
2. Design process and model building
Line 92 - 213 Chapter 2 actually contains a summary of the model activities. Overloading with information and limiting the role of the chapter as a methodological introduction makes it difficult to understand the direction and scope of the research. Please take this into consideration.
Line 102. Figure 1. Figure 'a' - linear dimensions do not have unit of measurement markings. Figure 'b' - is partially unreadable due to limited figure area and information density. Please improve the legibility of figure 'b'.
Line 107. Table 1. There is an evident lack of unit of measure designations for the listed parameter values. Please complete this. The numerical value should be supported by the unit of measurement.
There is an evident lack of reference, in the text of subsection 2.1, to Table 1. The information is found only in subsection 2.2 (Line 132). Please verify the reason for moving the reference for Table 1 and its correctness.
Line 109. „….from U=nϖD/60, V1m=Q/A,,….” The notation with a slash is colloquial and incomprehensible. Please explain clearly the intention of this coding.
I propose to use the mathematical formula generator and give the indicated notes sequential numbers and the correct appearance.
Line 111. „…CFD-POST….” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 128. Figure 2. The left part of the graphic design has illegible markings due to the small font size. Please homogenise the size of the additional information on the figure.
Lack of reference in the text of the article for Fig. 2. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 135. Table 2. There is a lack of reference in the text of the article to Table 2. Please complete this. The table cannot exist without a reason in the content of the paper. Lack of units of measurement in the description of numerical values. Please complete this.
Line 137. „….the sub-function ICEM of the commercial software ANSYS…” Please explain the abbreviation although it is common. Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 143. Figure 4. The system of XY axes that support the figure is illegible and makes it difficult to observe the explanations in the text of the manuscript (Line 141). Please improve the readability of key areas of Figure 4.
Line 145. Figure 5. the OY axis has no unit of measurement for the presented numerical values. Please complete this.
Line 157. The reference to Figure 5 can be found in a different subsection than 2.2. Please check the accuracy of the location of the reference in subsection 2.3 for Figure 5.
Line 148. „…Hm/Hc….” The notation with a slash is colloquial and incomprehensible. Indication of the unit of measure (ratio) "Hm/Hc” using a fractional dash is acceptable but is colloquial in meaning. However, exponential notation should be used.
Please use the notation of the quotient in units of measure (ratio) using mathematical notation with a power exponent for example: Hm·Hc-1.
Line 152. Figure 6. the axis of ordinates (OY) has a colloquial notation of the ratio Hm/Hc.
Please use the notation of the quotient in units of measure (ratio) using mathematical notation with a power exponent for example: Hm·Hc-1.
The unit of measure of the abscissa axis (OX) is not evident and should be indicated in the axis description.
Line 161. Figure 7. There is a lack of reference in the text of the article to Figure 7. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 182. The reference to Figure 6 can be found in a different subsection than 2.2. Please check the accuracy of the location of the reference in subsection 2.5 (2.5.1) for Figure 6.
Line 166. „….simulations[31]. ….” Line Please remember to put a space between the sentence content and the literature source, for example "....simulations [31]. ...."
Line 163, 165, „….SST….” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
Line 170. „….is set to 10-6 …..” Lack of a unit of measurement for a value or magnitude order.
Line 170. „…..3.867x10-4s……” The notation "X" as a multiplication sign is colloquial and should be replaced in the totation by the dot sign "·". There is a lack of space between the numerical value and the unit of measurement 's'. Please fill in the space.
Line 171. „….by 3° [32]. ….” Double space? Please verify the notation.
Line 174, 202. „….a0=33mm….” The unit of measure and value should be separated by a space. Please separate the main symbols and signs with spaces to increase the readability of the notation.
Line 177-178. Mathematical formulas (1) and (2). No reference in the text of the work to mathematical formulas . Please complete this. A formula or relation in a mathematical notation convention (model) cannot exist without a reason in the content of the paper.
Line 179. Figure 8. There is a lack of reference in the text of the article to Figure 8. Please complete this. The figure cannot exist without a reason in the content of the article. Very illegible and without units of measurement description for the axis of graph 8.
Line 213 Figure 8: Mistake in numbering of figures (Line 179 and Line 213)? Please correct the error. There is a lack of reference in the text of the manuscript to Figure 8 (Line 213). Please correct this. The figure cannot exist without a reason in the content of the article.
Line 186. Table 3. „….Q11(m3/s), n11 (r/min)….” Indication of the unit of measure (ratio) "m3/s” using a fractional dash is acceptable but is colloquial in meaning. However, exponential notation should be used.
Please use the notation of the quotient in units of measure (ratio) using mathematical notation with a power exponent for example: m3·s-1, r·min-1
A space is needed in the notation „….Q11(m3/s)…”
Table 3. There is a lack of reference in the text of the article to Table 3.. Please complete this. The table cannot exist without a reason in the content of the paper.
Line 202."....are shown in Table. ...." Visible lack of indicated table number. Please complete this.
Line 202 "...Only 393. 63 Pa. ...." Lack of grammatical correctness. Unintelligible, too laconic sentence. The space between the dot sign and the decimal and hundredths parts of the result is not correct. Please verify this occurrence in the entire text of the work.
Line 204. table 4. "....f(Hz)...." Please insert a space between the designation of the parameter and the unit of measurement.
Line 205. Table 5. „…â–³H/H…” Please use the notation of the quotient in units of measure (ratio) using mathematical notation with a power exponent for example: â–³H·H-1.
Table 5. There is no reference in the text of the article to Table 5. Please complete this. The table cannot exist without a reason in the content of the paper.
3. Results
Line 214 – 324.
The reader is surprised by the research activities undertaken due to the lack of a clear structure of the research scope. The discussion of the research results based on the comparison of own effects with those of other researchers is not adequately presented. Please supplement the content of the chapter with a solid discussion of the results. I propose to reformulate and complete the content of the chapter.
Line 216. Figure 9. The system of auxiliary axes (XYZ system) in figures: b, c, e is too small and illegible. Please correct this.
The red indicator arrows have unreadable arrowheads. It is difficult to interpret the vector turn. Please correct this.
Line 217, 220, Figure 10, "....t5=T..." No space between the parameters (t, T) and the "equals" (=) sign.
Line 236-237. Figure 10. There is a lack of reference in the text of the work to Figure 10. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 264. Figure 11. There is a lack of reference in the text of the work to Figure 11. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 290-291 Mathematical formulas (3), (4), (5), (6). No reference in the text of the work to mathematical formulas . Please complete this. A formula or relation in a mathematical notation convention (model) cannot exist without a reason in the content of the paper.
Line 292, 293. „… (m/s)….”, „…. (m/s2)…” Please use the notation of the quotient in units of measure (ratio) using mathematical notation with a power exponent for example: m·s-1, m·s-2 .
Line 294. Table 6. „...â–³h1-2...”. The lack of space between the numerical value and the parameter sign makes this notation difficult to understand.
The apparent lack of units of measurement for the numerical values presented makes the information difficult to understand.
Line 300. Figure 12. There is a lack of reference in the text of the work to Figure 12. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 300-301. Figure 13. There is a lack of reference in the text of the work to Figure 13. Please complete this. The figure cannot exist without a reason in the content of the article.
Line 312. „….dimensionless CPs of….” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
The notation „CP” is different from the notation in Figure 13. This is confusing. Please unify the manner in which the content is communicated.
4. Conclusions
Line 325-347.
References, in the text of the chapter, to results in graphical form (graphs, figures) are not supported by the ordinal numbers of the figures and tables. This makes it difficult for readers to understand the information. There is a lack of numerical values and units of measurement of parameters which, when cited, will demonstrate the expected effect of the goal of the work.
Line 326 – 328. „….In this paper, a pumped storage single-stage, vertical shaft reversible turbine is used as a model to explore the effect of changing the airfoil shape on the internal flow characteristics of the tail pipe of a reversible turbine, while keeping other over-flow components unchanged. …..”
Precise information about the goal of the work should be given each time and unambiguously in the summary, introduction and methodology. Especially perfunctory and limited information about the purpose of the work at the end of chapter 1 "introduction" is not in line with the conclusion. To evaluate the value of the results of the work, the logical scope of the research should also be presented much earlier. The level of coherence and the logical sequence of the content in all chapters of the work should be rethought.
Author Response
Many thanks to the experts for their valuable comments on this thesis, and the corresponding changes have been made based on the experts' comments.
Author Response File: Author Response.docx
Reviewer 4 Report
The current paper a pumped storage single-stage, vertical shaft reversible turbine is used as a model to explore the effect of changing the airfoil shape on the internal flow characteristics of the tail pipe of a reversible turbine, while keeping other over-flow components unchanged. The theory is validated using experiments.
Comments to authors:
- Please add more details of how the theory from the first sections is applied in the results section.
- In the current paper the authors talk about optimization, why no optimization function is specified. What optimization algorithm authors?
- The mathematical model of the process can be added
- The authors can add the steps of implementing the algorithms. The theoretical part can be better detailed. The steps will be in the benefit of the readers, maybe they’ll help the readers to implement the proposed algorithm.
- Add the measurement units labels for ordinate for all the figures from the paper.
- The state of the art it is very poor regarding representative papers, maybe the author could add the following publications:
o Hybrid Data-Driven Fuzzy Active Disturbance Rejection Control for Tower Crane Systems, European Journal of Control, vol. 58, pp. 373-387-11, 2021.
o Enhanced P-type Control: Indirect Adaptive Learning from Set-point Updates, IEEE Transactions on Automatic Control, DOI: 10.1109/TAC.2022.3154347, 2022.
- Add the both the advantages and the disadvantages of the proposed method, in the current version of the paper only the advantages are presented.
Author Response
Many thanks to the experts for their valuable comments on this thesis, and the corresponding changes have been made based on the experts' comments.
Round 2
Reviewer 3 Report
Manuscript
Title: „Influence of Guide Vane Profile Change on Tailpipe Flow Characteristics of Water Pump Turbine”
New title: Influence of Guide Vane Profile Change on Draft Tube Flow Characteristics of Water Pump Turbine
Authors: LI Qifei, Lu XIN, Gengda XIE, Siqi LIU, Qifan Wang
Dear Authors
I have reviewed the revised version of the articleI: "Influence of Guide Vane Profile Change on Draft Tube Flow Characteristics of Water Pump Turbine" submitted to the “Processes” Journal. The suggested corrections are visible in the content of the article but require a comment from the reviewer.
Line 2-3. Article topic
The topic of the paper has been modified, the modification better representing the addressed research question.
Abstract:
The content of the summary, in its revised version, still operates with general statements of the effects of realisation. In my opinion, symbolic changes do not realise the concept of objective presentation of results. Please take this into consideration.
Keywords: reversible water turbines; wing change; tailpipe vortex belt; pressure pulsation; energy, recovery factor;
New Keywords: reversible water turbines; wing change; draft tube vortex belt; pressure pulsation; energy recovery factor;
In the revised version, the topic „Guide Vane Profile Change” is not represented in the Keywords modification. Please take this into account.
1. Introduction
The indicated, main problems of the chapter have been resolved. No critical additional comments.
2. Design process and model building
Line 121. the introduced mathematical formulas have been placed in the text of the article paragraph. The result of the work should take the form of separating the formulas out of the paragraph outline and adding ordinal numbers. Please consider such actions.
Line 159. Figure 5. The description of the XY axis is incomplete for the figure and without the unit of measure indications. Please take this into account.
Line 162. The introduced mathematical formula was placed in the body of the text. The effect of the modification should look like separating the formula outside the paragraph outline and adding an ordinal number. Please consider such actions.
Line 198. Table 3. „…Flow rate Q11(m3·s -1 )….” Lack of spaces in notation
Most of the problems of the chapter have been resolved. No further critical comments.
3. Results
Line 241. Figure 10. The figure still has unresolved problems with the readability of graphic elements. Please take this into consideration.
Line 266-267. Figure 11. The figure has unresolved problems with lack of space in the data description notation on the OX axis.
Line 322-323. Mathematical formulas (3), (4), (5), (6). No reference in the text of the work to mathematical formulas . Please complete this. A formula or relation in a mathematical notation convention (model) cannot exist without a reason in the content of the paper.
Line 357. „….Cp ….” Please explain the introduced abbreviations of terms, possibly as soon as they are introduced in the content of the article. A single explanation is sufficient in the execution of the explanation.
The notation of the Cp parameter is different to the previous version, presented in Fig. 15 as a quotient notation DH·H-1. The abandonment of the previous notation introduces misinformation into the content of the article. Please take this into consideration. Please unify the manner in which the content is communicated.
A discussion of the results based on the literature sources appeared in Chapter 3. The discussion is extremely frugal in content and residual but realises the most important comment here. There are no other critical comments.
4. Conclusions
The content of the chapter better presents the achievements of the research. The representation of the research results is very limited and references to key results and their graphical and numerical representation are scarce throughout. There are no other critical comments.
Author Response
Thanks again for your valuable comments, it has now been revised.
Author Response File: Author Response.docx
Reviewer 4 Report
The current paper has been seriously improved. The authors answered to all my concerns. From my point of view the paper can be accepted as contribution in Processes Journal.
Author Response
Thanks again for your valuable comments, it has now been revised.
