Nonlinear Phenomena in Anisotropic Convection

技术摘要：研究倾斜地层中受压气体的热对流问题。之所以选择这个系统，是因为它非常适合研究各向异性模式形成系统中的多参数分岔。与液晶电对流（EC）等实验相反，用加压气体进行对流实验的主要优点是，我们很好地理解了描述流体流动的基本方程。加压气体允许在大型系统中进行实验（类似于EC），在这些系统中，边界效应很弱，并且保留了许多空间自由度。此外，通过改变温度和压力，可以实现广泛的参数范围。将对弱非线性区域进行研究，并与最近的理论研究进行定量比较。非技术文摘：本研究的目的是对非线性、非平衡模式形成现象进行实验研究。作为一个范例，浮力驱动的对流流动将在相对于水平倾斜的流体层中进行研究。从物理学的角度来看，这个系统非常有趣，在加热和冷却技术中也很重要。利用环境温度下的加压气体作为工质，可以在良好控制的边界条件下实现空前大系统尺寸的对流电池。预计边界效应将很弱，大部分空间自由度将被保留。这项研究将允许与最近的理论研究进行详细的定量比较。＊＊＊

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. ***