Rayleigh-Bénard convection in 3He near its critical point

International audienceWe study by direct numerical simulation the Rayleigh-Bénard convection in supercritical 3He using an anelastic approximation. The latter is based on scaling analysis associated with asymptotic expansions of the full governing equations which has an important consequence for numerical integration of the model. The approximate equations are supplemented by a parametric state equation and are solved numerically by a finite difference method coupled with a projection method. Numerical results giving time evolutions of the temperature difference between the horizontal walls are calculated and compared to experimental data. The convection onset is examined for the studied configuration