Numerical study of the wake induced by a porous disk under deflected inflow

Abstract

This study examines the wake of a porous disk that generates a velocity deficit equivalent to that of a wind turbine. Three-dimensional unsteady numerical simulations based on the finite volume method are performed. The URANS-SST (k-ω) model is applied for the turbulence closure. Two investigations are carried out in this study: (i) the influence of the disk porosity on the wake, for porosities values (p) ranging from 0 to 0.55 in the case of a perpendicular flow; and (ii) the influence of the yaw angle on the wake deviation, for yaw angles ranging from 5°to 30°. Good agreements with the available experimental data are obtained for the mean x-velocity component. The results confirm that wake length increases as porosity decreases. For nonporous disks, most part of the fluid is deflected toward the mast and above the disk. The y-velocity contours highlight two contra-rotating vortices in the vicinity of the disk. In both cases (nonporous and porous disks), a high turbulent kinetic energy is obtained near the disk area, with a higher maximum value for the nonporous disk.