Effect of ambient conditions near the interface on flow instability Original Research Article

The appearance and the development of thermoconvective oscillatory flows are investigated experimentally and numerically in a liquid bridge (LB) filled by 10 cSt silicone oil (Pr ≈ 108). The experiments were carried out under terrestrial conditions using the shielding of a liquid bridge. It allows to create different temperature distributions in the ambient gas near the interface. The 3-D numerical simulations have been done using parameters as close as possible to the experimental conditions. The dependence of viscosity upon temperature is taken into account. Both results are in an excellent agreement for the determination of the critical temperature difference. The different heat transfer possibilities at the free surface are analyzed.