Validation of the Beddoes–Leishman dynamic stall model for horizontal axis wind turbines using MEXICO data

Abstract

The aim of this study is to assess the load predicting capability of a classical BeddoesLeishman dynamic stall model in a horizontal axis wind turbine (HAWT) environment, in the presence of yaw-misalignment. The dynamic stall model was tailored to the HAWT environment, and validated against unsteady thick airfoil data. Subsequently, the dynamic stall model was implemented in a blade element-momentum (BEM) code for yawed flow, and the results were compared with aerodynamic measurements obtained in the MEXICO (Model Rotor Experiments under Controlled Conditions ) project on a wind turbine rotor placed in a large scale wind tunnel. In general, reasonable to good agreement was found between the BEM model and MEXICO data. When large yawmisalignments were imposed, poor agreement was found in the downstroke of the movement between the model and the experiment. Still, over a revolution the maximum normal force coefficient predicted was always within 8% of experimental data at the inboard stations, which is encouraging especially when blade fatigue calculations are being considered.

Comparative Study of Dynamic Stall under Pitch Oscillation and Oscillating Freestream on Wind Turbine Airfoil and Blade

“…Pereira et al [10] have proven that it is unrealistic to disregard the leading-edge separation, because the wind turbine airfoils are thick. The main features and formulae of the B-L dynamic stall model may be summarized as follows.…”

“…Finally, the nonlinear pitching moment coefficient is obtained by Equation (14), and a rotational increment is added as well. According to the recommendations of Pereira et al [10] and Gupa et al [11], the set of corresponding empirical time constants, T p , T f , T v , T vl , is as follows: 1.7, 8.0, 1.0, and 7.0, where T p and T f are related to the first-order lag of the leading-edge separation and trailing-edge separation, respectively, and both T v and T vl are the non-dimensional time constants related to the movement of the dynamic vortex.…”

“…An apparent advantage of the B-L model is that it yields good results with relatively few empirical coefficients, most of which can be derived from the static airfoil data. Despite the original application to helicopters (compressible flow), the B-L model has been introduced into wind turbines with several modifications [8][9][10][11]. Another promising method is the computational fluid dynamics (CFD) simulation achieved by numerically solving the Navier-Stokes equations with a suitable turbulence model.…”

Simulating Dynamic Stall Effects for Vertical Axis Wind Turbines Applying a Double Multiple Streamtube Model

“…Figure 1 shows an example of the force response of a pitching blade, simulated by the the LB model, and the features described above are present. Previous studies has shown that two iterations are sufficient to approach convergence for the LB model [11,24]. Therefore, the LB model runs two loops during each iteration of the DMS model.…”

“…An overview of the dynamic stall models adapted for the VAWTs applications can be found in [11,12]. The Gormont model [13], modified by Massé and Berg [14,15], is widely used for VAWTs simulations due to its simplicity of implementation [16][17][18][19][20].…”