Heat transfer at the phase interface of bubbles collapsing in subcooled liquids and during subcooled boiling

Abstract

Heat transfer phenomena with bubble condensation in subcooled liquids and during subcooled boiling are discussed, which were studied by using holographic interferometry. This inertialess and non-intrusive measuring technique allows interesting insights into fluid dynamics and thermodynamics of phase change processes. The resistance for the heat transport through the phase boundaries is mainly on the liquid side and therefore the heat transfer coefficient can expressed by simple correlations following the procedure in forced convective flow. For the sake of simple boundary conditions first bubble condensation in subcooled liquids with constant and homogenous temperature are studied and than the more complex situation with large temperature gradients in the wall near boundary during subcooled boiling are discussed.