HAMILTONIAN AND ONSAGERISTIC APPROACHES IN THE NONLINEAR-THEORY OF FLUID-PERMEABLE ELASTIC CONTINUA

A new system of equations governing nonlinear dynamics of fluid-permea ble poro-elastic media is derived on the basis of Hamilton's principle for reversible effects and the Onsager-Sedov approach for irreversibl e effects. The equations are in Eulerian variables, suitable for deali ng with fluid and solid phenomena simultaneously. The classical (Murna ghan-like) equations of nonlinear elasticity, as well as the governing equations of the ideal and Navier-Stokes fluids are shown to be speci al cases of the general governing system. It is well-known that the Na vier-Stokes equations of compressible fluid provide a correct self-con sistent basis for studying a wide variety of nonlinear effects in flui ds. The authors believe that the governing system proposed here provid es the same opportunities for various nonlinear effects in poro-elasti c fluid-penetrable media. Copyright (C) 1996 Elsevier Science Ltd.