Turbulent Kinetic Energy Distribution around Experimental Permeable Spur Dike

Round 1

Reviewer 1 Report

The aim of the reviewed manuscript is to investigate the turbulent kinetic energy distribution close to a permeable spur dike, varying the submergence degree, the porosity and the void size. The study is based on an experimental campaign conducted in the laboratory, during which velocity measurements were performed.

I personally found the topic and the experimental activity interesting. However, the description of the experiments and the discussion of the results should be improved in order to highlight the actual value of the work.

In the light of the above I recommend the manuscript for possible publication after a revision.

Please, see the following comments.

P1 L16: “It increases, decreases…., and increases…” Please, rephrase because it seems contradictory.

Introduction: In few cases, the results obtained by the different Authors in their work are described. In other cases, it is only written which are the investigated conditions. I suggest improving the introduction in this sense, in order to highlight the novelty of the study.

P2 L68-69: Give also the flow velocity.

P2 L73: The Authors must explain how they performed velocity measurements, describing the instrument and the settings used, as well as the data treatment.

Table 1: Give a name to each run, in order to use the corresponding name in the comments.

P3 L82: each variable must be explained. The Authors have to include also references for the TKE equation (see for example, Penna, N., Coscarella, F., D’Ippolito, A., & Gaudio, R. (2020). Bed roughness effects on the turbulence characteristics of flows through emergent rigid vegetation. Water, 12(9), 2401).

Figures: use colours in the figures. The title of the y-axis should be “TKE” with the corresponding units.

Figure 2: why did the Authors use for h=17 cm the third section?

P6 L124: “…is the smallest at 0.2h, the largest at 0.6h and the largest at 0.8h.” To me, there should be only one “smallest value” and only one “largest value”. Therefore, the description of the results must be modified according to this comment, because many time in the manuscript the Authors used such kind of sentence. I suggest also going beyond the merely description of the trends, trying to provide a physical justification each time.

Conclusions: They should be revised including the implications of the study.

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Turbulent kinetic energy distribution around experimental permeable spur dike”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:

Reviewer #1:

• P1 L16: “It increases, decreases…., and increases…” Please, rephrase because it seems contradictory.

Response: Thank you very much for the comments on the paper. We have checked and proofread the manuscript. In addition, we have corrected the language errors in the article.

• Introduction: In few cases, the results obtained by the different Authors in their work are described. In other cases, it is only written which are the investigated conditions. I suggest improving the introduction in this sense, in order to highlight the novelty of the study.

Response: Thank you very much for the comments on the paper. We have restated the introduction section in the revised manuscript.

• P2 L68-69: Give also the flow velocity.

Response: Thank you very much for the comments on the paper. We have made additions in the revised manuscript.

• P2 L73: The Authors must explain how they performed velocity measurements, describing the instrument and the settings used, as well as the data treatment.

Response: Thank you very much for the comments on the paper. We have made additions in the revised manuscript.

• Table 1: Give a name to each run, in order to use the corresponding name in the comments.

Response: Thank you very much for the comments on the paper. We have corrected it in the revised manuscript.

• P3 L82: each variable must be explained. The Authors have to include also references for the TKE equation (see for example, Penna, N., Coscarella, F., D’Ippolito, A., & Gaudio, R. (2020). Bed roughness effects on the turbulence characteristics of flows through emergent rigid vegetation. Water, 12(9), 2401).

Response: Thank you very much for the comments on the paper. We have corrected it in the revised manuscript.

• Figures: use colours in the figures. The title of the y-axis should be “TKE” with the corresponding units.

Response: Thank you very much for the comments on the paper. We have corrected it in the revised manuscript.

• Figure 2: why did the Authors use for h=17 cm the third section?

Response: Thank you very much for the comments on the paper. I'm really sorry that this is a clerical error of the author, and we have corrected it.

• P6 L124: “…is the smallest at 0.2h, the largest at 0.6h and the largest at 0.8h.” To me, there should be only one “smallest value” and only one “largest value”. Therefore, the description of the results must be modified according to this comment, because many time in the manuscript the Authors used such kind of sentence. I suggest also going beyond the merely description of the trends, trying to provide a physical justification each time.

Response: Thank you very much for the comments on the paper. We have redescribe it in the revised manuscript.

• Conclusions: They should be revised including the implications of the study.

Response: Thank you very much for the comments on the paper. We have restated the conclusion of the paper in the revised manuscript.

Reviewer 2 Report

The manuscript entitled "Turbulent kinetic energy distribution around experimental permeable spur dike " has been reviewed. This paper aims to explore the distribution of the turbulent kinetic energy around a spur dike using a laboratory flume. While the subject of the manuscript is very interesting, it is not well written and contains important flaws that make it very hard to generalize the findings. Some general and minor comments are provided below.
 
English: the language of the manuscript is very poor and needs to be revised thoroughly by a native. In some cases, it is very hard to get the purpose of the authors.

-Abstract: The Abstract describes the findings qualitatively. It is better to add some quantitative results as well.
-Introduction: This section is somewhat organized better than other sections. Again, the poor language makes it hard to read. The authors have used the word “law” several times while its usage seems to be redundant, for example,  “variation law of water flow force”, “variation law of water surface line”, “distribution law of turbulent kinetic energy”. The authors have used some unique expressions that are not very common in the literature. For example, on page 1 Line 36, the authors have said that “… sediment start-up by on-site sediment start-up test”. One may guess that the authors talk about the sediment movement and it’s better to replace start-up by sediment threshold or incipient of motion. The authors have used both “groin” and “spur dike”. While they are the same, it is suggested that one of them be used throughout the text for consistency. While the authors argue that “the influence of factors such as water depth, porosity, and pore size on the turbulent kinetic energy near the permeable spur dike is analyzed by the combination of flume model test and theoretical analysis” nothing can be found regarding the theoretical analysis in the manuscript.
 
-Physical model
. It would be better if a dimensional analysis be carried out first to find the effective parameters in the study and also to make the results applicable in other situations. While the flow velocity components are the main parameters measured in the study, the authors have not provided any information about the velocity measurement apparatus. Also, the flow around the spur dike is completely three-dimensional. How do the authors make sure that the “three-point method” is a good representative of the flow field? How the porosity values were measured? What is the unit of the digits in Figure 1? What criteria were used for the design of the spur dike? In Table 1, “quantity of flow” should be replaced by “Flow rate or Discharge”.
 
-Results “while there is not such a heading in the manuscript!”
The presentation of the results is superficial. The authors just have reported their experimental observations without providing any analysis. The unit of the vertical axis is not provided in all of the figures. The “left band” in the title of the horizontal axis seems to be replaced by “left bank”. The authors are strongly recommended to use Metric units. The authors can validate and compare their results with those of previous studies.

Conclusion
It seems just a summary of the results. The conclusion usually aims to generalize the findings of the study and explore its limitations. The authors have used the word “dam” in the conclusion instead of spur dike. Why? A dam is completely different from a spur dike.

Author Response

Dear Editors and Reviewers:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Turbulent kinetic energy distribution around experimental permeable spur dike”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:

Reviewer #2:

• English: the language of the manuscript is very poor and needs to be revised thoroughly by a native. In some cases, it is very hard to get the purpose of the authors. 

Response: Thank you very much for the comments on the paper. First of all, I'm sorry for our poor English writing. We have polished the language section in the revised manuscript.

• Abstract: The Abstract describes the findings qualitatively. It is better to add some quantitative results as well.

Response: Thank you very much for the comments on the paper. We have redescribed the abstract in the revised manuscript.

• Introduction: This section is somewhat organized better than other sections. Again, the poor language makes it hard to read.

Response: Thank you very much for the comments on the paper. We have made additions in the revised manuscript.

• Physical model: It would be better if a dimensional analysis be carried out first to find the effective parameters in the study and also to make the results applicable in other situations. While the flow velocity components are the main parameters measured in the study, the authors have not provided any information about the velocity measurement apparatus. Also, the flow around the spur dike is completely three-dimensional. How do the authors make sure that the “three-point method” is a good representative of the flow field? How the porosity values were measured? What is the unit of the digits in Figure 1? What criteria were used for the design of the spur dike? In Table 1, “quantity of flow” should be replaced by “Flow rate or Discharge”.

Response: Thank you very much for the comments on the paper. We have supplemented the dimensional analysis of the experimental section and the range of experimental flow rates. According to previous researches, the flow velocity from the surface to the bottom of the river increases first, reaches the maximum, and then decreases. If the river depth is h, the maximum flow rate is at 0.1-0.3h, the average flow rate is at 0.6h, and the minimum flow rate is near the bottom of the river. Therefore, the “three-point method” is a good representative of the flow field. The experimental model spur dike is designed according to the typical spur dike parameters in the upper reaches of the Yangtze River. Porosity was measured with professional measuring instruments.

• -Results “while there is not such a heading in the manuscript!” The presentation of the results is superficial. The authors just have reported their experimental observations without providing any analysis. The unit of the vertical axis is not provided in all of the figures. The “left band” in the title of the horizontal axis seems to be replaced by “left bank”. The authors are strongly recommended to use Metric units. The authors can validate and compare their results with those of previous studies.

Response: Thank you very much for the comments on the paper. We re-analyzed the trial results based on expert advice.

• Conclusion
  It seems just a summary of the results. The conclusion usually aims to generalize the findings of the study and explore its limitations. The authors have used the word “dam” in the conclusion instead of spur dike. Why? A dam is completely different from a spur dike.

Response: Thank you very much for the comments on the paper. We have rewritten the conclusion section and fixed language errors.

Round 2

Reviewer 1 Report

I appreciate the efforts done by the Authors in reviewing the manuscript.

I suggest modifying L96 as follows:

"The turbulent kinetic energy (TKE) of water flow can be calculated by the following equation, which is commonly used in several works (e.g. Penna et al., 2020):"

At L101 modify the sentence as follows:

"where u', v' and w' are the temporal velocity fluctuation in the stremwise, spanwise and vertical directions"

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Turbulent kinetic energy distribution around experimental permeable spur dike”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have studied comments carefully and have made correction which we hope meet with approval. Revised portion are marked in red in the paper.

Reviewer 2 Report

The authors have revised the manuscript according to the comments. The new version is much better than the previous version. I have one suggestion that should be applied by the authors before publishing. As stated in my previous review, the "spur dam" is not a common term and it should be replaced by "spur dike" throughout the manuscript.

Author Response

Dear Reviewer:

Thank you for your letter and for the reviewers’ comments concerning our manuscript entitled “Turbulent kinetic energy distribution around experimental permeable spur dike”. Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have replaced the "spur dam" as "spur dike" in the Revised Manuscript.