BISTABLE STATES OF THERMAL CONVECTIONAL FLOW IN POROUS MEDIA
多孔介质中的双稳热对流

The behaviour of bifurcations for thermal convectional flow in porous media, with respect to two parameters: bifurcational Rayleigh number and auxiliary aspect ratio of rectangular porous media, is studied. Attention is focused on those values of the aspect ratio at which, the two lowest critical Rayleigh numbers are near each other. We found the secondary bifurcation of the thermal convectional flow by means of the Liapunov-Schmidt reduction, and give the asymptotical expansions of the primary and secondary branches of these steady solutions. The analysis of stabilities indicates that the primary branch bifurcated from the secondary critical point becomes stable from unstable if the secondary bifurcation point is stridden. Thus this branch and the stable primary branch developed from the first critical point form bistable states of thermal convectional flow.