J. Phys. IV France 11 (2001) Pr6-65-Pr6-71
Direct numerical simulation of the time-dependent convection in a supercritical fluid layer : Temporal evolution of the convective structures in highly non-linear regimesI. Raspo1, S. Aumaître2, B. Gilly2, P. Bontoux2 and B. Zappoli2
1 CNES/DP/MP/SC, 18 avenue Edouard Belin, 31401 Toulouse cedex 04, France
2 LMSNM, FRE 2405 CNRS, IMT, La Jetée, Technopôle de Château-Gombert, 38 rue Frédéric Joliot Curie, 13451 Marseille cedex 20, France
We present a numerical study of the hydrodynamic stability of a supercritical fluid (more precisely CO2) contained in a 2D square bottom - heated cavity (Rayleigh - Bénard configuration). The fluid is initially at rest, at thermodynamic equilibrium and set at some Kelvins above its critical temperature. Due to the characteristic properties of near - critical fluids, the heating of the lower wall induces the development of two thin boundary layers of temperature and density along the two (hot below and cold above) walls which are separated by a quasi - isothermal bulk. We studied the stability of these two boundary layers by solving the time - dependent compressible Navier - Stokes equations written for a Van der Waals gas.
© EDP Sciences 2001