3-DIMENSIONAL SIMULATION OF PENETRATIVE CONVECTION - PENETRATION BELOW A CONVECTION ZONE

We perform full three- dimensional numerical simulations to study the behaviour of penetrative compressible convection below a deep stratified stellar-type convective envelope. The domain of computations is divided into three distinct regions; the upper 2 % and the lower 40% is kept convectively stable while the middle 58 % is made unstable to convection. Four series of solutions have been computed by varying the polytropic index and thus the stability of the lower stable layer. The penetration distance is found to decrease as the stability of the region beneath the convection zone is increased.