Comparative CFD study of the effect of the presence of downstream turbines on upstream ones using a rotational speed control system

Abstract

Comparative CFD study of the effect of the presence of downstream turbines on upstream ones using a rotational speed control systemTo cite this article: S-P Breton et al 2014 J. Phys.: Conf. Ser. 555 012014 View the article online for updates and enhancements. Related contentTurbulence characteristics in a free wake of an actuator disk: comparisons between a rotating and a non-rotating actuator disk in uniform inflow H Olivares-Espinosa, S-P Breton, C Masson et al. Abstract.The effect of a downstream turbine on the production of a turbine located upstream of the latter is studied in this work. This is done through the use of two CFD simulation codes, namely OpenFOAM and EllipSys3D, which solve the Navier-Stokes equations in their incompressible form using a finite volume approach. In both EllipSys3D and OpenFoam, the LES (Large Eddy Simulation) technique is used for modelling turbulence. The wind turbine rotors are modelled as actuator disks whose loading is determined through the use of tabulated airfoil data by applying the blade-element method. A generator torque controller is used in both simulation methods to ensure that the simulated turbines adapt, in terms of rotational velocity, to the inflow conditions they are submited to. Results from both simulation codes, although they differ slightly, show that the downstream turbine affects the upstream one when the spacing between the turbines is small. This is also suggested to be the case looking at measurements performed at the Lillgrund offshore wind farm, whose turbines are located unusually close to each other. However, for distances used in today's typical wind farms, this effect is shown by our calculations not to be significant.

Impact of Wind Veer and the Coriolis Force for an Idealized Farm to Farm Interaction Case

“…The turbines are introduced into the simulations using an actuator disc method (ACD) based on airfoil data [19]. A generator-torque controller is used to adjust each turbine's rotational speed in the variable flow in a realistic way [20]. Both the ACD and the atmosphere i.e., turbulence and wind shear are introduced using body forces in the incompressible Navier Stokes (NS) equations formulated in vector notation, see Equation (1).…”

Direct Measurements of Turbulence and Flow Characteristics of a Vertical Axis Wind Turbine Using the Eddy Covariance Method

“…Although there are numerous studies on numerical simulations of wind turbine flows [8][9][10][11][12][13], there are limited literature on direct measurements of flow and turbulence characteristics of VAWTs. Breton et al [14] revealed that the upstream distance between turbines affect turbine performance and hence the turbulence distribution pattern in front of a turbine was observed and presented in this work in addition to the wake (or downwind) of the VAWT. Numerical modeling tends to underestimate turbulence and flow fields [15], and thus, by using the EC method, this paper presents a comprehensive direct measurements of turbulence and flow of upwind and wake of the VAWT.…”