Flow around a bubble on a heated wall in a cross-flowing liquid under microgravity condition

Fluid motion around a bubble placed on a heated wall of a flowing liquid channel is studied under microgravity condition, using a spectral element based two-dimensional numerical model. It is shown that the flow and temperature fields around the bubble are governed by an interaction between thermocapillary and forced convection. An opposing interaction between the two convection mechanisms creates a recirculation cell at the downstream side of the bubble. Channel flow velocity, length of the heated wall before the bubble, and temperature difference between the heated wall and the bulk liquid are shown to be the most important variables. Their effects on the bubble surface temperature, surface velocity, stagnation point on the bubble surface, length of the recirculation cell along the heated wall, and wall heat transfer near the bubble are investigated.