Pragmatic models: BEM with engineering Add-Ons

This chapter discusses several aspects related to engineering methods in wind tur bine design codes. Current engineering models for rotor aerodynamics topic are built around the Blade Element Momentum (BEM) theory. The Blade Element Momentum theory in itself is very basic, e.g., it is derived for two-dimensional, stationary, homogenous, and non...

An efficient blade sweep correction model for blade element momentum theory

New vortex-lift and tangential-force models for HAWT aerodynamic load prediction

Horizontal axis wind turbines (HAWTs) experience three-dimensional rotational and unsteady aerodynamic phenomena at the rotor blades sections. These highly unsteady three-dimensional effects have a dramatic impact on the aerodynamic load distributions on the blades, in particular, when they occur at high angles of attack due to stall delay and...

Global sensitivity analysis of model uncertainty in aeroelastic wind turbine models

A framework is presented for performing global sensitivity analysis of model parameters associated with the Blade Element Momentum (BEM) models. Sobol indices based on adaptive sparse polynomial expansions are used as a measure of global sensitivities. The sensitivity analysis workflow is developed using the uncertainty quantification toolbox...

Evaluation of different methods for determining the angle of attack on wind turbine blades with CFD results under axial inflow conditions

This work presents an investigation on different methods for the calculation of the angle of attack and the underlying induced velocity on wind turbine blades using data obtained from three-dimensional Computational Fluid Dynamics (CFD). Several methods are examined and their advantages, as well as shortcomings, are presented. The investigations...

An engineering model for wind turbines under yawed conditions derived from high fidelity models

This work presents a significantly improved engineering model for the prediction of the loads in yawed flow. The newly developedmodel focuses on the so-called skewedwake effect. This effect leads to an azimuthal variation of the axial induction velocity which depends on the yawangle, tip speed ratio,wind speed, andradial position.Theazimuthal...