Characterizing Turbulence in the Background Flow and Wake of a Stationary Porous Disk: A Two-phase Wind Tunnel Study Under Dry Conditions*

Some US offshore sites can experience intense precipitation, which warrants investigating its impact on wind turbine performance. This work is the preliminary part of a study on the influence of inertial particles on the wake dynamics of a stationary porous disk. The first part of the work focuses on the experimental design and construction of a two-phase wind tunnel, emphasizing the achievement of quasi-homogeneous isotropic turbulence (HIT) in the open tunnel configuration with inflow wind conditions without the inertial particles, also referred to as 'dry conditions.' Constant Temperature Anemometry (CTA) hotwire measurements are performed to characterize turbulence in the background flow in the tunnel, including investigating the effects of adding honeycombs, screens, and spray grids on the flow quality. In addition, 2D Computational Fluid Dynamic (CFD) studies are performed to complement this experimental work with an emphasis on enhancing the flow quality in the tunnel. The second part of the work involves studying the turbulence in the wake of a stationary porous disk under dry conditions. Turbulence statistics are calculated for the near and far wake of the porous disk and compared against the background flow in the open tunnel configuration.