Near-wake behavior of an asymmetric wind turbine rotor

Yen, Pin Chun; Li, YuanTso; Scarano, Fulvio; Yu, Wei

doi:https://doi.org/10.5194/wes-10-1775-2025

Articles | Volume 10, issue 9

https://doi.org/10.5194/wes-10-1775-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/wes-10-1775-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 10, issue 9

Research article

|

01 Sep 2025

Research article |

| 01 Sep 2025

Near-wake behavior of an asymmetric wind turbine rotor

Pin Chun Yen, YuanTso Li, Fulvio Scarano, and Wei Yu

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Final revised paper (published on 01 Sep 2025)
Preprint (discussion started on 17 Oct 2024)

Interactive discussion

Status: closed

RC1:
'Comment on wes-2024-122', Anonymous Referee #1, 12 Dec 2024

See comments in the supplemental PDF. In general, I recommend this manuscript to be reconsidered after some major revisions, mainly:
1) Add in the introduction and possibly also in the conclusions a better elaboration on what the added value of this research is in the larger wind energy science context.
2) Clean up the language of the manuscript. I marked some sentences that are hard to read or understand, but there were plenty more that I did not mark, especially in the second part of the paper. I would seriously consider having a writing specialist go through the paper for this purpose, as I feel the level of English is currently sub-par and at some moments simply sloppy.
3) Improve quality of the captions; right now, none of the figures are comprehensible without reading the accompanying text.
4) Clean up the mathematical nomenclature used in the manuscript. Parameters are regularly not used consistently or not defined at all, making it hard to understand or reproduce the work.
5) Consider moving/renaming some sections/paragraphs around as suggested in the PDF.

Citation: https://doi.org/10.5194/wes-2024-122-RC1
- AC1: 'Comment on wes-2024-122, reply to the reviewers', Wei Yu, 31 Mar 2025
  
  We sincerely appreciate the three reviewers for their time and thoughtful feedback on our manuscript. The point to point responses to their comments are provided in the attached document.
  
  Citation: https://doi.org/10.5194/wes-2024-122-AC1
RC2:
'Comment on wes-2024-122', Anonymous Referee #2, 04 Jan 2025

Please see attached document for comments.

Citation: https://doi.org/10.5194/wes-2024-122-RC2
- AC1: 'Comment on wes-2024-122, reply to the reviewers', Wei Yu, 31 Mar 2025
  
  We sincerely appreciate the three reviewers for their time and thoughtful feedback on our manuscript. The point to point responses to their comments are provided in the attached document.
  
  Citation: https://doi.org/10.5194/wes-2024-122-AC1
RC3:
'Comment on wes-2024-122', Anonymous Referee #3, 09 Jan 2025

Please see attached PDF file.

Citation: https://doi.org/10.5194/wes-2024-122-RC3
- AC1: 'Comment on wes-2024-122, reply to the reviewers', Wei Yu, 31 Mar 2025
  
  We sincerely appreciate the three reviewers for their time and thoughtful feedback on our manuscript. The point to point responses to their comments are provided in the attached document.
  
  Citation: https://doi.org/10.5194/wes-2024-122-AC1
AC1: 'Comment on wes-2024-122, reply to the reviewers', Wei Yu, 31 Mar 2025

We sincerely appreciate the three reviewers for their time and thoughtful feedback on our manuscript. The point to point responses to their comments are provided in the attached document.

Citation: https://doi.org/10.5194/wes-2024-122-AC1

Peer review completion

AR: Author's response | RR: Referee report | ED: Editor decision | EF: Editorial file upload

AR by Wei Yu on behalf of the Authors (31 Mar 2025) Author's response Manuscript

EF by Mario Ebel (02 Apr 2025) Author's tracked changes

ED: Referee Nomination & Report Request started (15 Apr 2025) by Emmanuel Branlard

RR by Anonymous Referee #1 (02 May 2025)

Suggestions for revision or reasons for rejection

First of all, I would like to congratulate the authors on the substantial improvements made to the manuscript. The current version of the manuscript is of much higher quality than the original manuscript, and in my humble opinion meets the minimum requirements for publication in Wind Energy Science. That being said, I would still suggest the following minor revisions to improve the quality of the paper:
- In the introduction, the authors state that "The primary objectives are to provide insights into whether rotor asymmetry can serve as a viable passive strategy to accelerate wake recovery and to assess both its potential benefits and limitations." However, responding to one of my comments in Section 3, the authors say "However, this work focuses on quantifying the effects of blade length differences on leapfrogging instability and its growth rates. However, this work focuses on quantifying the effects of blade length differences on leapfrogging instability and its growth rates". If the primary objective of this paper is to assess the viability of rotor asymmetry to accelerate wake recovery, quantifying the wake recovery rate or wake breakdown location seems to me of vital importance. I therefore maintain my initial position that the authors should seriously consider adding this analysis to the paper to strengthen their findings.
- Similarly, I still have concerns about the differences in findings between this manuscript and Abraham et al. (2023b). The authors give a hypothesis that might explain the differences, but do not investigate this hypothesis. I suggest that the authors consider including simulations in their manuscript that test this hypothesis. This would verify the validity of the model presented and used in the manuscript, and subsequently strengthen the findings substantially.

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RR by Anonymous Referee #2 (02 May 2025)

ED: Publish subject to minor revisions (review by editor) (15 May 2025) by Emmanuel Branlard

AR by Wei Yu on behalf of the Authors (22 May 2025) Author's response Author's tracked changes Manuscript

ED: Publish as is (03 Jun 2025) by Emmanuel Branlard

ED: Publish as is (04 Jun 2025) by Sandrine Aubrun (Chief editor)

AR by Wei Yu on behalf of the Authors (05 Jun 2025) Manuscript

Short summary

This study explores how changing wind turbine blade length affects the aerodynamics behind the turbine. Using high-fidelity simulations, we found that varying blade lengths accelerates the leapfrogging event but does not improve wake recovery directly. In contrast, turbulence plays a bigger role, as the wake breakdown process is more influenced by it over the studied rotor asymmetries. These findings provide insights for designing more efficient wind turbine rotors.