Study on aerodynamic and structural performance of floating offshore wind turbine with fusion winglets

ABSTRACT

The surge motion of the platform affects the aerodynamic and structural performance of the floating offshore wind turbine (FOWT) with tip-fusion winglets. Hence, this paper aims to study the aerodynamic and structural performance of the wind turbine with and without tip-fusion winglets under the surge motion by ANSYS software. Comparison of the differences in the pressure distribution, flow fields, modal analysis, and stress of the wind turbines under surge motions. The results show that the tip-fusion winglets have an obvious influence on the pressure distribution and flow fields, and the influence mainly concentrates on the tip of the blade. In addition, the frequency of the wind turbine with fusion winglets is less than without winglets from the first mode to the third mode. The main vibration type of wind turbines with and without winglets is flapping. Besides, the maximum stress of the wind turbine with fusion winglets is increased by 19.91%, and there is a stress concentration phenomenon at the connection between the blade tip and the winglet, which is easy to cause fatigue damage. The location of the maximum stress appears in the transition section between the Cylinder airfoil and the DU airfoil.

CO EDITOR-IN-CHIEF:

• Ou, Yu-Chen

ASSOCIATE EDITOR:

• Ou, Yu-Chen

KEYWORDS:

• Offshore wind turbine
• fluid-structure interaction
• aerodynamic and structural performance
• fusion winglet
• surge

Nomenclature

Asurge	=	the amplitude of the surge motion
BEM	=	Blade Element Momentum
CFD	=	Computational Fluid Dynamic
FOWT	=	Floating Offshore Wind Turbine
FSI	=	Fluid-structure interaction
GRP	=	Glass Fiber Reinforced plastics
M	=	the output torque of the wind turbine
n	=	the speed of 12.1 r/min under the rated condition of wind turbines
P	=	the output power of the wind turbine
P0	=	the rated output power of the wind turbine P0 = 5 MW
6-DOF	=	Six degrees-of-freedom
RANS	=	Reynolds-Averaged Navier-Stokes Equations
t	=	time
UDF	=	User defined function
V	=	the incoming wind speed
Vind	=	the induced velocity of platform motion
Vrel	=	the relative velocity
Vs	=	the platform’s relative inflow velocity during surge motion
VS	=	the relative inflow velocity under surge motion
Vx	=	the partial velocities in the directions of X
Vy	=	the partial velocities in the directions of Y
Vz	=	the partial velocities in the directions of Z
α	=	the angle of attack
β	=	the pitch angle
Βsurge	=	the displacement of the surge motion
βs’urge (t)	=	the velocity of surge motion at each moment
εsurge	=	the frequency of the surge motion
δ	=	the relative error

Acknowledgments

This paper is supported by the National Key R&D Program of China (2023YFB4203301). And this research work is sponsored by research funds from Shanghai’s 2020 Annual Science and Technology Innovation Action Plan: Social Development and Science & Technology Project (No. 20dz1205302). Additionally, the support of the Non-carbon energy conversion and utilization institute under the Shanghai Class IV Peak Disciplinary Development Program is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the National Key R&D Program of China (2023YFB4203301), Shanghai’s 2020 Annual Science and Technology Innovation Action Plan: Social development and Science & Technology Project (No. 20dz1205302) and Non-carbon energy conversion and utilization institute under the Shanghai Class IV Peak Disciplinary Development Program. Data Availability Statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.