Experimental and computational study of channelized water waves generated by a porous body

Abstract

We report about experiments on large amplitude shallow water waves that were generated by the sudden forward motion of a porous wedge-type piston. The experiments are compared with those done previously [7] when the motion of a body with impervious boundary was examined. Close agreement is obtained between the two sets of experiments if the porous body is sealed at its rear side, but differences are substantial without the seal. The theoretical model is based upon the shallow water assumption and an unsteady non-Darcy flow in an isotropic porous medium. The transfer of momentum from the porous body to the interstitial fluid is effected by a Darcy-Forchheimer type interaction, thus introducing two free parameters which must be determined through matching with experiments. A finite difference scheme with flux corrected transport is used to integrate these equations. Numerical results agree favorably with those from observations.