UNSTEADY THERMOSOLUTAL OPPOSING CONVECTION OF LIQUID WATER MIXTURE IN A SQUARE CAVITY .2. FLOW STRUCTURE AND FLUCTUATION ANALYSIS

Abstract

Effects of buoyancy ratio on the flow structure and fluctuating characteristics of the velocity, temperature and concentration fields are numerically investigated for a liquid-water mixture cavity subject to opposing horizontal thermal and solutal buoyancies at high thermal and solutal Rayleigh numbers. Three different flow structures, namely, the multilayer, mixed and secondary cell flows, were predicted. Time histories and power spectra for flow variables probed at several locations indicate that the flow is highly unstable. The collision of the thermally and solutally driven cells causes the secondary cell flow to be chaotic. Moreover, flow bifurcation is noted.