Modelling dynamic stall of an airfoil with vortex generators using a
double-wake panel model with viscous-inviscid interaction
Abstract
Vortex generators (VGs) have been widely applied to wind turbines thanks
to their potential to increase aerodynamic performance. Due to the
complex inflow perceived by a rotor and the proneness to flow
separation, VGs on wind turbines usually experience highly unsteady
flow. While there are models that exist to simulate the steady effects
of VGs, we lack a fast and efficient tool to model the unsteady
performance of airfoils equipped with VGs. This paper adopts an unsteady
double-wake panel model with viscous-inviscid interaction developed to
simulate a vertical axis turbine in dynamic stall, adding the capability
of predicting the dynamic aerodynamic performance of VG-equipped
airfoils. The results of a series of steady and unsteady cases of an
airfoil with different VG configurations in various pitch motions in
free and forced transition are verified against experimental data.
Results show that the double wake model offers sufficient accuracy
results compared to experimental data to claim the model’s validity in a
preliminary evaluation of an airfoil’s capability to prevent stall with
VGs. While a few limitations are still identified for improvement, the
model’s accuracy in predicting the transition location, separation and
reattachment, and drag forces into future development.