Mass transport in water waves propagated over a permeable bed

Mass transport in water waves propagated over a permeable bottom is investigated. Boundary-layer approximations are incorporated into the Lagrangian equations of motion, and the mass transport velocity is obtained for both monochromatic and random waves. It is found that inside the permeable bed, although the Eulerian steady streaming vanishes, the mass transport always exists in the direction of wave propagation. The effects of porosity and permeability of the porous bed on the mass transport are discussed.