Assessment of Aerodynamic Plates Subjected to Von Kármán Vortex Street for Enhancing the Wind Energy Generation in Blade-Less Devices

Round 1

Reviewer 1 Report

This paper is well written and interesting. The introduction of this paper provides a good explanation of its contributions. The review of previous researches and the inspiration gained from them are structured in a nice-to-follow manner. Its study problem and methods are also clearly stated. The authors used dynamic modeling and a multi-objective optimization approach, identified multiple key variables and verified the positive impact of Von Kármán vortex street on a plate downstream of a rigid cylinder.

However, it could be further enhanced. Some minor recommendations are as follows:

(1) About the Equation 20 "α is a user-setting parameter". How exactly is the user-setting done? Is it based on experience or something else? I think the authors should provide further information and explanation.

(2) As for the Figure 13: Diagram of optimisation process methodology. I want to know how the complexity of the computing in the optimisation process.

(3) The description of figures in the text sometimes uses Figure x, and sometimes uses Fig. x. Please unify them. It would be better if other similar situations could be handled together.

(4) There are many abbreviations in the text, and when they first appear, it might be better to use the full name, even though some of them are well known to the readers.

(5) The review of previous researches is not very comprehensive and novel. Please add relevant studies from the last three years to support this paper.

I encourage the authors to refine their paper to make it available for publication in the journal.

Author Response

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Reviewer 2 Report

The authors have presented the development of the surrogate model for blad behind a cylinder.  Even work was presented well, there certain concerns to be addressed 

1. what was Re for the present work. Mention this in the Abstract. 

2. It was said that authors have used 3D LES simulations but for 3D simulation, 2.2 million cells is a very small grid. what was the domain size in z-direction? what was the grid size in the Z direction?

3. how would results would change you solve the plate behind the cylinder with 6 DOF. 

 

The language used for the manuscript is good and understandable  

Author Response

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Reviewer 3 Report

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Minor revision is required for the language.

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Reviewer 4 Report

The paper investigates the process of energy generation by a plate in the wake region of a vortex street. The subject is novel. However, there are major problems with this study:

1. This bladeless device generates energy by the rotation of a plate, but the authors study the effect of plate size by fixing the plate in the wake region, does the optimal size of the plate in this case apply to the motion condition? Is there a correlation between plate size and vibration frequency? Can the root mean square of the lift force through a fixed position represent the energy obtained in motion? These important issues are not clearly explained by the authors.

1. Lines 23-24 are incorrectly expressed. Low manufacturing complexity, low maintenance cost and low noise are not challenges, but advantages of small wind turbines.

2. The last two sentences of the second paragraph of the first section should be switched in order, otherwise the logic does not make sense.

3. Figure 5 is too sketchy to convey the planning of this article. Suggest revising it to add details.

4. The study of the paper extracts energy through Carmen vortex, then the mesh of the trailing region at the rear of the cylinder should need to be refined, especially since the LES simulation requires high mesh resolution and a smaller aspect ratio in the depth direction. However, the maximum grid used in the realistic paper of Figure 14 is only about 200000, which is too little for a 3D simulation. This makes the reviewer wonder about the accuracy of the calculation. Please show the mesh in three dimensions in the text.

5. Several final conclusions are not fully explained in the text. For example, in the second article, the maximum power coefficient is 0.269, but the reviewer did not find the relevant analysis in the paper. The authors should show the reader how these conclusions were obtained.

Extensive editing of English language required

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Round 2

Reviewer 2 Report

The manuscript is really improved a lot, and it can be accepted in the current form

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Reviewer 4 Report

The authors answered all questions and the quality of the manuscript has improved. However, there are errors in citing all references and image serial numbers in this article, which should be double-checked by the authors when submitting the manuscript!

Author Response

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