Impact of aerodynamic modelling on seakeeping performance of a floating vertical axis wind turbine

Abstract

This study focuses on the impact of the aerodynamic model on the dynamic response of a floating vertical axis wind turbine (VAWT). It compares a state‐of‐the‐art quasi‐steady double multiple streamtube (DMS) solver, a prescribed vortex wake (PVW), and a free vortex wake (FVW) solver. The aerodynamic loads acting on a bottom‐fixed VAWT and computed with the three aerodynamic solvers are compared, then the dynamic responses of the floating turbine in irregular waves and turbulent wind with the different aerodynamic solvers are compared. Differences are observed, particularly in the mean motions of the platform. Eventually, the aerodynamic damping computed by the solvers are estimated with aerodynamic simulations on the turbine with imposed surge and pitch motions. The estimated damping can then be correlated with the dynamic response amplitude of the VAWT. Substantial discrepancies are observed between the three solvers at high tip speed ratio, when the rotor is highly loaded. It is shown that the quasi‐steady DMS solver seems to give greater amplitude of motions for the floating VAWT because of strong rotor/wake interaction that are not correctly accounted for.

High-Reynolds-number investigations on the ability of the full-scale e-TellTale sensor to detect flow separation on a wind turbine blade section

“…The NACA 65 4 -421 profile has different slope modifications of the static lift coefficient corresponding to different states of flow on the suction side surface of the airfoil. This profile has already been studied in the work of Devinant et al (2002), and a modified version (rounded trailing edge) of this NACA profile was used in the ANR (French national grant) project SMARTEOLE (Leroy, 2018;Braud and Guilmineau, 2016;Baleriola et al, 2018;Jaunet and Braud, 2018).…”

High Reynolds investigations on the ability of the full scale e-TellTale sensor to detect flow separation on a wind turbine blade section

“…The NACA-65 4 -421 profile has different slope modifications of the static lift coefficient corresponding to different states of flow on the suction side surface of the airfoil. This profile was already studied in the work of (Devinant et al, 2002) and a modified version (rounded trailing edge) of this NACA profile was used in the ANR (French national grant) project SMARTEOLE (Leroy, 2018;Braud and Guilmineau, 2016;Baleriola et al, 2018;Jaunet and Braud, 2018). Measurements of the present study were performed with a turbulence intensity of 1%, which may be at the origin of some discrepancies in the exact values of the separations angles.…”