SOME REMARKS ON THE ACOUSTIC PARAMETERS OF SHARP-EDGED POROUS-MEDIA

This work revisits some numerical experiments by Smeulders et al, [Sme ulders DMJ, Van Hassel RR, Van Dongen MEH, Jansen JK. Int. J. Eng. Sci . 1994;32(6):979]. It concerns the acoustic properties of two-dimensio nal porous media whose pore surface is rugged, Contrary to what is inf erred by Smeulders et al., we discover that Johnson's shape factor, M, remains finite and is in the order of unity if the surface is not cus ped. However, in agreement with Smeulders et al,, M --> + infinity whe n the pore surface has a sharp edge whose angle tends to zero. (C) 199 8 Elsevier Science Ltd. All rights reserved.