Hydraulic Characteristics of Flow over a Highly Permeable Porous Structure

The present study is carry out to investigate the velocity fields and turbulence characteristics of the flow over permeable structures by channel experiment in low water level. Detailed measurements of the time-averaged velocity components, turbulence intensity components of permeable and solid structures are taken by the acoustic doppler velocimeter (ADV). The characteristic feature of porous medium is permeable, and the vertical distributions of time-averaged velocities above permeable structures are more uniform than solid structure due to the slip velocity at the fluid/porous interface. The turbulence intensity above structure with large porosity are slightly greater than small porosity structure, and the permeable structures have smaller turbulence intensity than solid structure around the structures. The results show that the porous medium reduces the turbulence intensity, and then reduce the scour to structures.