Nonlinear Phenomena in Anisotropic Convection

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9320124 Bodenschatz Technical abstract: The investigation is concerned with the thermal convection of pressurized gases in an inclined layer. This system has been chosen since it is ideally suited for the study of multiparameter bifurcations in anisotropic pattern-forming systems. An experiment in convection of pressurized gases, opposed to, for example, electroconvection of liquid crystals (EC), has the major advantage that the fundamental equations describing the fluid flow are well understood. Pressurized gases allow experiments (similarly to EC) in large systems, where boundary effects are weak and much of the spatial degrees of freedom are retained. In addition, by changing the temperature and pressure a wide range in parameters can be achieved. The weakly nonlinear region will be investigated and quantitatively compared with recent theoretical investigations. Non-technical abstract: The aim of this research is th experimental investigation of nonlinear, non-equilibrium pattern- forming phenomena. As a paradigm buoyancy-driven convective flow in a fluid layer which is inclined with respect to the horizontal will be studied. This system is of great interest from a physics point of view as well as of major importance in heating and cooling technology. By using pressurized gases at ambient temperatures as working fluids convection cells with unprecedented large system sizes under well controlled boundary conditions can be realized. It is expected that boundary effects will be weak and much of the spatial degrees of freedom will be retained. The research will allow a detailed quantitative comparison with recent theoretical investigations. ***