Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Numerical investigation of shallow-water effects on hydrokinetic turbine wake recovery

O'Doherty, Tim ORCID:, Thompson, David S., Bhushan, Shanti and El Fajri, Oumnia 2020. Numerical investigation of shallow-water effects on hydrokinetic turbine wake recovery. International Marine Energy Journal 3 (1) , pp. 25-35. 10.36688/imej.3.25-35

[thumbnail of 46-Article Manuscript-296-1-10-20200513.pdf] PDF - Published Version
Available under License Creative Commons Attribution.

Download (1MB)


Thrust, power and intermediate wake predictions obtained using resolved rotating blade with sliding mesh simulations for a hydrokinetic turbine (HKT) are assessed using the open-source flow solver OpenFOAM. Single- and two-phase URANS and DES computations are performed for three-blade, 0.5m diameter (D) turbine mounted on a stanchion that intersects the free surface with a tip-speed ratio λ = 6.15. The thrust and power predictions compare within 5% of the experimental data. Results show that the thrust predictions are dominated by the pressure distribution on the blades, whereas the shear stress plays a significant role in the power predictions. The turbine performance showed unsteadiness with amplitudes around 3% of the mean, due to the disruption of the flow each time a blade passed in front of the stanchion. The wake recovery is primarily due to the growth of shear layers (originating from the blade tips) towards the turbine axis, which are primarily caused by the cross-plane turbulent velocity. The shear layer growth is enhanced by the turbulence produced by the stanchion. Predictions of the mean wake profile compared within 10% of the experimental data, which is significant improvement over previous Fluent predictions that showed large errors of 22%. The improved predictions in OpenFOAM is attributed to better turbulence predictions. Two-phase results show that the interaction between the wake and free-surface is initiated by the interaction of stanchion with the free-surface. The free-surface creates a blockage effect that accelerates the flow in the upper bypass region and enhances the wake recovery.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Engineering
Additional Information: This work is licensed under a Creative Commons Attribution 4.0 International License.
ISSN: 2631-5548
Date of First Compliant Deposit: 26 March 2021
Date of Acceptance: 25 March 2020
Last Modified: 09 Nov 2022 10:37

Citation Data

Cited 1 time in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item


Downloads per month over past year

View more statistics