Dynamic Stall on Airfoils with Leading-Edge Tubercles: Characterization of the Dynamic Stall Vortex by Simulations and Experiments

Inspired by the leading-edge protuberances found on the flippers of humpback whales, tubercles have drawn significant interest for improving airfoil aerodynamic performance. In static conditions, airfoils with tubercles exhibit a softer onset of stall and increased lift in post-stall regime, though with a reduced maximum lift coefficient....

Modeling dynamic stall of an airfoil with vortex generators using a double-wake panel model with viscous–inviscid interaction

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...

Developing a double-wake vortex-panel method model capable of simulating dynamic stall with vortex generators for wind turbine design applications

Towards high-fidelity aero-servo-elasticity analysis

The development of a high-fidelity fluid-structure interaction tool for the simulation of aircraft flight dynamics in the subsonic flow regime is presented. The tool combines a high-fidelity large-eddy simulation code with an immersed boundary method, a multibody solver and a loose coupling scheme between fluid and solid. The development of the...

Controlling dynamic stall using vortex generators on a wind turbine airfoil

Vortex generators (VGs) have proven their capabilities in wind turbine applications to delay stall in steady flow conditions. However, their behaviour in unsteady conditions is insufficiently understood. This paper presents an experimental study that demonstrates the effect of VGs in unsteady flow, including controlling and suppressing the...

Pressure based active load control of a blade in dynamic stall conditions

A proportionate controller is investigated experimentally for unsteady load alleviation purposes on a 2D wing model with a trailing edge flap. This study is supposed to be a simplified version of a Smart Rotor, a mechanism which deals with the reduction of unsteady loads acting on a wind turbine and aims to understand the behavior of this type...

An Investigation of Dynamic Stall using a LBM-VLES Approach

Horizontal Axis Wind Turbines (HAWTs) are a very popular source of renewable energy, but these machines are often subject to off-design conditions owing to the unsteady nature of wind. Unsteady aerodynamic conditions have been associated with cyclic loading of turbine blades, which can have hugely detrimental effects on their operational life....

Near-wake flow simulation of a vertical axis turbine using an actuator line model

In the present work, the near-wake generated for a vertical axis wind turbine (VAWT) was simulated using an actuator line model (ALM) in order to validate and evaluate its accuracy. The sensitivity of the model to the variation of the spatial and temporal discretization was studied and showed a bigger response to the variation in the mesh size...

A comparison of dynamic stall models and their effect on instabilities

Aeroelastic codes are fundamental for the design of wind turbines and the prediction of instabilities. Such codes rely on engineering models which limit their accuracy. With wind turbine blades becoming more slender to lower the costs, it is important to reduce these uncertainties to maintain a safe and stable turbine design. The dynamic stall...

Dynamic Stall Modeling for Wind Turbines

Modern wind turbines frequently operate at off-design conditions during their life cycle. They undergo dynamic loads characterized by unsteady aerodynamics. Predicting these unsteady aerodynamic loads has been very difficult due to the non-linear nature of unsteady aerodynamics. Especially when operating near the stall region, these turbine are...

Estimating the angle of attack from blade pressure measurements on the national renewable energy laboratory phase VI rotor using a free wake vortex model: Yawed conditions

Nonlinear Aeroelastic Study of Stall Induced Oscillation in a Symmetric Airfoil

In this paper the aeroelastic stability of a wind turbine rotor in the dynamic stall regime is investigated. Increased flexibility of modern turbine blades makes them more susceptible to aeroelastic instabilities. Complex oscillation modes like flap/lead-lag are of particular concern, which give way to potential structural damage, see...

Nonlinear Aeroelastic Study of Stall Induced Oscillation in a Symmetric Airfoil

In this paper the aeroelastic stability of a wind turbine rotor in the dynamic stall regime is investigated. Increased flexibility of modern turbine blades makes them more susceptible to aeroelastic instabilities. Complex oscillation modes like flap/lead-lag are of particular concern, which give way to potential structural damage, see...