Large-eddy simulation of turbulent flow past wind turbines/farms: the Virtual Wind Simulator (VWiS)

Abstract

A large‐eddy simulation framework, dubbed as the Virtual Wind Simulator (VWiS), for simulating turbulent flow over wind turbines and wind farms in complex terrain is developed and validated. The wind turbines are parameterized using the actuator line model. The complex terrain is represented by the curvilinear immersed boundary method. The predictive capability of the present method is evaluated by simulating two available wind tunnel experimental cases: the flow over a stand‐alone turbine and an aligned wind turbine array. Systematic grid refinement studies are carried out, for both single turbine and multi‐turbine array cases, and the accuracy of the computed results is assessed through detailed comparisons with wind tunnel experiments. The model is further applied to simulate the flow over an operational utility‐scale wind farm. The inflow velocities for this case are interpolated from a mesoscale simulation using a Weather Research and Forecasting (WRF) model with and without adding synthetic turbulence to the WRF‐computed velocity fields. Improvements on power predictions are obtained when synthetic turbulence is added at the inlet. Finally the VWiS is applied to simulate a yet undeveloped wind farm at a complex terrain site where wind resource measurements have already been obtained. Good agreement with field measurements is obtained in terms of the time‐averaged streamwise velocity profiles. To demonstrate the ability of the model to simulate the interactions of terrain‐induced turbulence with wind turbines, eight hypothetical turbines are placed in this area. The computed extracted power underscores the significant effect of site‐specific topography on turbine performance. Copyright © 2014 John Wiley & Sons, Ltd.

Numerical Study on the Effect of Air–Sea–Land Interaction on the Atmospheric Boundary Layer in Coastal Area

“…The LES is performed using an in-house numerical code called Virtual Wind Simulator (VWiS) [7][8][9]. Let x 1 , x 2 , and x 3 (or, x, y, and z) denote the the streamwise, spanwise, and vertical directions, respectively.…”

“…The Poisson equations are solved using an open-source math library called Portable, Extensible Toolkit for Scientific Computation (PETSc) [12]. The details of VWiS are given in Yang et al [7].…”

“…With the use of the IB method, there is no need to generate topography-conforming grid, and simulations can be performed using efficient flow solvers on regular Eulerian grid. The CURVIB-LES code has been extensively validated for many applications [7,14,[16][17][18][19]. The land elevation is obtained from the database of the National Oceanic and Atmospheric Administration (NOAA).…”

“…In the collaborative numerical study, we have developed a novel computational framework to perform large-eddy simulation (LES) of atmospheric boundary layer (ABL) with field measurement data and realistic land topographies incorporated into the simulations. The complex topographies of land, such as dunes, beaches, and rivers, are directly captured in our simulation using the immersed boundary (IB) method [7], such that we do not need to use flat-surface approximation with surface roughness variation only. The LES results are compared with field measurements and simulations of Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) [4].…”

Development of a quantitative analysis system for greener and economically sustainable wind farms

“…Wind farms can be accurately modelled using CFDWake and a blade element momentum solver, but this requires data about the wind turbine, which is not usually known and has a high computational cost. Yang et al (2015) developed the "Virtual Wind Simulator"…”