Permeable media are encountered in a wide variety of geophysical systems. A particular type of such media is “hybrid porous media” which consists of a fluid-saturated porous bed bounded by a free-stream flow. The study of pore-space turbulence in hybrid porous media is of major importance as it controls mixing and governs the kinetics of the bio-chemical processes within the hyporheic zone, as well as sediment dynamics.

To this end, the Ven Te Chow Hydrosystems Laboratory has implemented the Illinois Hyporheic Flow Facility -IHFF-. The IHFF consists of a flume with an idealized permeable bed made by packing uniform size spheres in cubic arrangement. Measurements of the streamwise and wall-normal velocities in the free and pore-space flows are performed with standard 2-D PIV and endoscopic PIV, respectively. Our measurements allow us to study of the fluid dynamics of the free and pore flows and their interaction.