Influence of Airfoil Curvature and Blade Angle on Vertical Axis Hydraulic Turbine Performance in Low Flow Conditions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 The paper based on the hydrodynamic performance of traditional vertical axis turbines, utilized numerical calculations and experimental methods to investigate the influence of blade helicity and airfoil curvature on the energy conversion efficiency of vertical axis turbines in low flow velocity, which is interesting, but there are some questions need to be addressed:

1.The formatting of all figures and tables should be standardized and improved.

2. The language need to be polished.

3. A Nomenclature table is missing—this should be clearly defined.

4. The novelty of this work should be emphasized and highlighted.

5. The conclusion should be more quantified.

6. the mesh indenpendence test should improved, at least four meshs number, the work maybe helpful: Fuel 381, 133303.

7. how is the turbine performance defined ?  the work maybe helpful: Applied Energy 356, 122361

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

the points of criticism reported in the following require detailed elaboration to rise the quality of your paper to the journal level.

1) The abstract should be more concise and better structured. It should start with a clear introduction to the background, followed by an explanation of the addressed literature gap, the methodologies utilised, and the typology of results achieved.

2) State of the art should be rephrased to provide an insight of the processes and technologies analysed. At present, it is a list of literature contributions. This would help in stating the novelty of the paper, which is currently not evident.

3) The experimental setup lacks detailed justification regarding the key parameters considered such as the selected range of flow velocities and the specific values of the helical angles and airfoil curvatures tested.

4) The description of the numerical model is overly general and lacks precision. Specific details regarding domain discretisation and computational choices are vague and need to be clearly stated, including explanations for these choices. Information on the number, size, and distribution of elements, as well as the growth ratio of the elements, should be included. The simplifications made and their impact on the results should be discussed to ensure the accuracy of the model. A sensitivity analysis of spatial discretisation and time step size should be presented with appropriate graphs and detailed discussions. Additionally, the method used to model the rotation and translation of the turbine must be described. Key computational settings should be fully disclosed to enable replication of the simulations..

5) The experimental validation is limited in scope and does not adequately support the numerical analysis conducted. The study uses a simplified setup with limited parameters for the validation of the power coefficient and torque. However, VATs in practical applications operate under diverse and unsteady flow conditions that would affect the parameters considered.

6) The presentation of results does not provide a discussion on the physical motivations determining the obtained data. The current comments mainly describe the data without detailing the underlying causes of the observed outcomes.

7) In the conclusions section, the statements should be supported by numerical data. At present, they are completely missing.

8) The level of English needs to be improved. The mistakes present should be corrected.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

accept it

Author Response

Your comments and suggestions are of great significance for improving the quality of the paper. Thank you for taking the time and energy to review the paper and give constructive feedback and suggestions. Thank you for your attention and support, and look forward to further cooperation in the future. Good luck with your work! 

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

the replies provided during the review process should be connected with tangible amendments to the text of the paper draft. This is referred in particular to the justification of the key parameters considered in the analyses, the description of the numerical model, and the discussion of the presented results.

The experimental validation proposed is limited in scope and does not adequately support the numerical analysis carried out. This should be clearly stated and commented on inside the paper as it is a major limitation of the presented research.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

all the points of criticism were adequately addressed. Nonetheless, the corresponding amendments to the text are not sufficient. All the replies provided during the review process should be reflected in the paper.

Author Response

Thank you very much for your valuable opinions. The content of the paper has been revised and supplemented according to your suggestions.

Please see the attachment.

Author Response File: Author Response.pdf

Round 4

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

the criticism aspects were adequately addressed during the review process.