Forces on rapidly growing vapor bubbles on a wall in forced convection with varying angle of inclination

The forces involved in rapid vapor bubble growth are assessed by measurement and analysis of bubble growth in four principal orientations of the boiling surface and channel flow with respect to gravity. The approaching liquid flow is made nearly uniform to warrant the possibility to compute the added mass forces. Almost no difference in shape history is observed between the four cases. This is most remarkable for the case in which the boiling surface is facing downward with respect to gravity. By way of careful shape analysis and extensive force computations, the reason for this remarkable behavior is found to be the crucial role of the inertia force.