Ducted wind turbines in yawed flow: a numerical study

Dighe, Vinit; Suri, Dhruv; Avallone, Francesco; van Bussel, Gerard

doi:https://doi.org/10.5194/wes-6-1263-2021

Articles | Volume 6, issue 5

https://doi.org/10.5194/wes-6-1263-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Wind Energy Science Conference 2019

https://doi.org/10.5194/wes-6-1263-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 6, issue 5

Research article

|

22 Sep 2021

Research article |

| 22 Sep 2021

Ducted wind turbines in yawed flow: a numerical study

Vinit Dighe, Dhruv Suri, Francesco Avallone, and Gerard van Bussel

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Final revised paper (published on 22 Sep 2021)
Preprint (discussion started on 05 Sep 2019)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

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- Supplement

RC1: 'Ducted Wind Turbines in yawed flow: A numerical study', Anonymous Referee #1, 07 Oct 2019
- AC1: 'Response to referee #1', Vinit Dighe, 09 Oct 2019
RC2: 'Comments', Anonymous Referee #2, 18 Oct 2019
- AC2: 'Response to referee #2', Vinit Dighe, 22 Oct 2019

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Vinit Dighe on behalf of the Authors (22 Nov 2019) Author's response Manuscript

ED: Referee Nomination & Report Request started (17 Dec 2019) by Katherine Dykes

RR by Anonymous Referee #3 (06 Jan 2020)

Suggestions for revision or reasons for rejection

The paper investigates the aerodynamic performance of ducted turbines by means of computational fluid dynamics. The article is well-written and well-structured. It, however, contains several flaws in my view: First and foremost, the problem investigated here, although of high interest, lacks elements of novelty. The authors have presented simulations the main case using various simplified assumptions including neglecting the rotation effects (uniform disc loading for representing the turbine) and 3D effects. There are occasions where insufficient information is given: for example, in defining the 3D simulations, the number of mesh points and the lateral extent of the domain, as well as boundary conditions at the lateral planes, are not explained and the authors have only mentioned that a similar setup to 2D case is used. Finally, I believe more detailed analysis could be performed by looking into the 3D case and the associated flow fields generated.
Here's some detailed comments:
- Page 1, line 22: correct the sentence (there are ...)
- Page 3, line 2: why not including rotating actuator disc? and why not 3D?
- Page 4, 18: you mention "minimum" y+ of 1: do you mean "maximum" here? If your simulations are wall resolved, your yplus should be less than 1. Can you plot the y+ values across the ducts for the investigated cases? Same line: you mention standard wall function is used. Why do you use wall function at all? if your mesh is fine enough to resolve the boundary layer, wall functions should not be used.
- Page 4, line 21: Please explain what is a "fan" boundary condition. It is not a classic BC.
- Page 5, line 8: "multi-core" is a vague explanation. Explain how many cores is exactly used for the computations. Same page: line 10: add "camber" after cross-section. Can you explain what does D5 mean here?
- Page 6, fig 5: Please add both upper and lower sections of the duct (and/or write in the caption that this is the lower cross-section) and possibly with the use of colors make it more clear which lines correspond to which duct. It is a little unclear until you see figure 9.
- Page 6, line 15: why can the blockage effect be ignored in this scenario?
- Page 7: provide more details on the 3D case, a snapshot of the mesh, lateral extent, etc.
- Page 7, line 5: Provide more details on time averaging (how many iterations used for it? are figure 9 the time-averaged velocities or the instantaneous ones?)
Page 8, line 7: four times larger, but how many mesh points?
Page 10, line 14: Ok for the explanation of the fact, but can we hear what is the physics behind?
Page 11, line 6: This sentence looks a little paradoxical to me: "... DonQi D5 duct configuration not only demonstrates an insensitivity to yaw but a gain in the overall performance" does it alter the performance or is it insensitive after all?

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RR by Anonymous Referee #4 (24 Feb 2020)

ED: Reconsider after major revisions (23 Mar 2020) by Katherine Dykes

AR by Vinit Dighe on behalf of the Authors (16 Jun 2020) Author's response Manuscript

ED: Referee Nomination & Report Request started (06 Jul 2020) by Katherine Dykes

RR by Anonymous Referee #3 (21 Jul 2020)

RR by Paul van der Laan (31 Aug 2020)

ED: Reconsider after major revisions (01 Sep 2020) by Katherine Dykes

AR by Vinit Dighe on behalf of the Authors (23 Apr 2021) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (26 Apr 2021) by Katherine Dykes

RR by Paul van der Laan (07 May 2021)

ED: Reconsider after major revisions (17 May 2021) by Katherine Dykes

AR by Vinit Dighe on behalf of the Authors (28 Jun 2021) Author's response Manuscript

ED: Referee Nomination & Report Request started (29 Jun 2021) by Katherine Dykes

RR by Paul van der Laan (02 Aug 2021)

ED: Publish subject to minor revisions (review by editor) (10 Aug 2021) by Katherine Dykes

AR by Vinit Dighe on behalf of the Authors (11 Aug 2021) Author's response Manuscript

ED: Publish subject to technical corrections (16 Aug 2021) by Katherine Dykes

ED: Publish subject to technical corrections (19 Aug 2021) by Jakob Mann (Chief editor)

AR by Vinit Dighe on behalf of the Authors (27 Aug 2021) Author's response Manuscript

Short summary

Ducted wind turbines (DWTs) can be used for energy harvesting in urban areas where non-uniform flows are caused by the presence of buildings or other surface discontinuities. For this reason, the aerodynamic performance of DWTs in yawed-flow conditions must be characterized. It is found that the duct cross-section camber offers not only insensitivity to yaw but also a gain in performance up to a specific yaw angle; thereafter any further increase in yaw results in a performance drop.