Numerical Study of Transitional Unsteady Boundary Layer on Wind Turbine Airfoil Using Hybrid RANS/LES Turbulence Model

2018 ◽  
Author(s):  
Di Zhang ◽  
Daniel R. Cadel ◽  
Eric G. Paterson ◽  
Kevin T. Lowe
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Turbulence Model ◽  
Numerical Study ◽  
Unsteady Boundary Layer ◽  
Wind Turbine Airfoil

Numerical Study of Yawed Wind Turbine Under Unstable Atmospheric Boundary Layer Flows

2020 ◽  
Author(s):  
Dezhi Wei ◽  
Decheng Wan
Keyword(s):  
Boundary Layer ◽  
Atmospheric Boundary Layer ◽  
Wind Turbine ◽  
Numerical Study ◽  
Atmospheric Stability ◽  
Wind Farms ◽  
Total Power ◽  
Turbulent Structures ◽  
Ambient Turbulence ◽  
Turbine Wake

Abstract Turbine-wake interactions among wind turbine array significantly affect the efficiency of wind farms. Yaw angle control is one of the potential ways to increase the total power generation of wind plants, but the sensitivity of such control strategy to atmospheric stability is rarely studied. In the present work, large-eddy simulation of a two-turbine configuration under convective atmospheric boundary layer is performed, with different yaw angles for the front one, the effect of turbine induced forces on the flow field is modeled by actuator line. Emphasis is placed on wake characteristics and aerodynamic performance. Simulation results reveal that atmospheric stability has a considerable impact on the behavior of wind turbine, wake deflection on the horizontal hub height plane for yawed wind turbine is relatively small, compared with the result of the empirical wake model proposed for wind turbine operating in the neutral stratification, which is attributed to the higher ambient turbulence intensity and large variance of wind direction in the convective condition. And associated with the smaller wake deflection, the total power production does not increase as expected when yawing the upstream turbine. In addition, due to the existence of great quantities of disorganized coherent turbulent structures in the unstable condition, the yaw bearing moment experienced by the downstream wind turbine increases dramatically, even if the rotor plane of the first turbine is perpendicular to the inflow direction.

A comparative numerical study of four turbulence models for the prediction of horizontal axis wind turbine flow

2010 ◽  
Vol 224 (9) ◽  
pp. 1973-1979 ◽  
Author(s):  
N S Tachos ◽  
A E Filios ◽  
D P Margaris
Keyword(s):  
Wind Turbine ◽  
Turbulence Model ◽  
Numerical Study ◽  
Free Field ◽  
Turbulence Models ◽  
Horizontal Axis ◽  
Wind Condition ◽  
Computational Domain ◽  
Horizontal Axis Wind Turbine ◽  
Rans Equations

The analysis of the near and far flow fields of an experimental National Renewable Energy Laboratory (NREL) rotor, which has been used as the reference rotor for the Viscous and Aeroelastic Effects on Wind Turbine Blades (VISCEL) research program of the European Union, is described. The horizontal axis wind turbine (HAWT) flow is obtained by solving the steady-state Reynolds-averaged Navier—Stokes (RANS) equations, which are combined with one of four turbulence models (Spalart—Allmaras, k—∊, k—∊ renormalization group, and k—ω shear stress transport (SST)) aiming at validation of these models through a comparison of the predictions and the free field experimental measurements for the selected rotor. The computational domain is composed of 4.2×106 cells merged in a structured way, taking care of refinement of the grid near the rotor blade in order to enclose the boundary layer approach. The constant wind condition 7.2 m/s, which is the velocity of the selected experimental data, is considered in all calculations, and only the turbulence model is altered. It is confirmed that it is possible to analyse a HAWT rotor flow field with the RANS equations and that there is good agreement with experimental results, especially when they are combined with the k—ω SST turbulence model.

scholarly journals A NUMERICAL STUDY OF THE TURBULENCE MODEL INFLUENCE ON A SAVONIUS WIND TURBINE PERFORMANCE BY MEANS OF MOVING MESH

2019 ◽  
Vol 42 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Nopem Ariwiyono ◽  
Priyo A. Setiawan ◽  
Adi W. Husodo ◽  
Sudiyono . ◽  
Arief Subekti ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbulence Model ◽  
Numerical Study ◽  
Moving Mesh ◽  
Turbine Performance ◽  
Savonius Wind Turbine

scholarly journals Wall-Resolved LES Modeling of a Wind Turbine Airfoil at Different Angles of Attack

2020 ◽  
Vol 8 (3) ◽  
pp. 212 ◽  
Author(s):  
Irene Solís-Gallego ◽  
Katia María Argüelles Díaz ◽  
Jesús Manuel Fernández Oro ◽  
Sandra Velarde-Suárez
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Acoustic Waves ◽  
Urban Environments ◽  
Far Field ◽  
Noise Generation ◽  
Noise Propagation ◽  
Trailing Edge ◽  
Wind Turbine Airfoil ◽  
Les Model

Noise has arisen as one of the main restrictions for the deployment of wind turbines in urban environments or in sensitive ecosystems like oceans for offshore and coastal applications. An LES model, adequately planned and resolved, is useful to describe the noise generation mechanisms in wind turbine airfoils. In this work, a wall-resolved LES model of the turbulent flow around a typical wind turbine airfoil is presented and described in detail. The numerical results obtained have been validated with hot wire measurements in a wind tunnel. The description of the boundary layer over the airfoil provides an insight into the main noise generation mechanism, which is known to be the scattering of the vortical disturbances in the boundary layer into acoustic waves at the airfoil trailing edge. In the present case, 2D wave instabilities are observed in both suction and pressure sides, but these perturbations are diffused into a turbulent boundary layer prior to the airfoil trailing edge, so tonal noise components are not expected in the far-field noise propagation. The results obtained can be used as input data for the prediction of noise propagation to the far-field using a hybrid aeroacoustic model.

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