Effect of Swept Angle on Aerodynamic Force Generation of a Swept Twist Round (STR) Vertical Blade
ABSTRACT: This paper discusses
the effect of blade's swept angle towards the aerodynamic forces generation of
Vertical Axis Wind Turbine (VAWT). In the rotating condition, normal force
coefficient (Cn) and tangential force coefficient (Ct) are calculated by using Blade
Element Momentum Theory (BEMT)-based multiple streamtube model. Multiple
streamtube model calculation for three different tip speed ratios (TSR)
suggests that the variation of Cn and Ct are up to 3.3 times less for the model
with higher swept angle. For the startup condition, Computational Fluid
Dynamics (CFD) analysis using ANSYS CFX is conducted to calculate the torque
variation at twelve different blade positions relative to the wind direction
for seven different models. Unlike the Gorlov mathematical model for a helical
turbine, CFD analysis predicted that the average torque is increasing as the
swept angle increases. Meanwhile, the variation of torque is up to 10 times
less for the models with higher swept angle.
Author: Nanang Mahardika
Journal Code: jptmesingg170004