EXPERIMENTAL OBSERVATION ON SURFACE WAVE PHENOMENA IN THERMAL CAPILLARY CONVECTION

摘要

Free surface deformation is the most important physics phenomena in Fluid with free surface. In this paper, the surface deformation of convection in a rectangular cavity due to gravity and different temperature difference between two sidewalls have been investigated. The cavity is 52mm x 42mm in horizontal cross section and 4mm in height. Temperature difference is increased gradually, and the flow in liquid layer will change from steady convection to unsteady convection. An optical diagnostic system consisting of Michelson interferometer with image processor has been developed for studying of surface deformation in convection, it gives out the displacement of free surface oscillation. The present experiment demonstrates, that the surface deformation will be present in the convection, not only the hydrothermal wave instability but also the surface wave instability should be discussed in studying the mechanism of convection.