Determination of Velocity Profile Over and Through Porous Bed*

Objectives of this research is to present a unified method to determine the velocity profile over and through the porous bed and to compare this profile with velocity profile over impermeable bed. Equations for flow within bed (Navier-Stokes-Forchheimer) and above the porous bed (Navier-Stokes) are solved, which lead to generate a velocity profile. Theoretically, it is found that for flow within bed, the laminar velocity distribution is expressed by a Jacobi elliptical function. The turbulent velocity distribution also follows a Jacobi elliptical function but compounded with a power of log function. Experimentally, a tracer was injected in the sand bed and its peak concentration was observed at different locations. A fiber optics based sensor was developed to measure the refractive index of water at different locations in the bed to determine the flow velocity. An ADV is used to measure flow velocity above the bed. Ansys Fluent software is used to simulate flow field in porous bed and above the porous bed numerically. We found that our theoretical results well matched with experimental and numerical results which proves the validity of theoretical equations.