Bifurcation phenomena in flows of a nematic liquid crystal

Results are presented of an experimental investigation of cellular flows in a nematic liquid crystal cell with physical dimensions comparable to the t hickness of a human hair. Finite geometry effects have been exploited to in vestigate detailed bifurcation events which combine to give complicated flo ws in some parameter regimes. Initially observed flows consist of either si x or eight convection cells which possess maximum symmetry consistent with the boundary conditions. These states undergo symmetry-breaking and Hopf bi furcations as the control parameter is continuously changed and interaction s of the critical events are found to generate Silnikov dynamics. At strong er forcing it is possible to obtain both ordered fluid motion, consisting o f square convection cells, and microturbulence.