Instabilities in Mixed Convection at Moderate and Strong Magnetic Fields

该项目旨在研究液态金属流经受强磁场影响的矩形管道时的传热和传质。更具体地说，这项工作探讨的假设，在完全湍流抑制的条件下，由磁场，热对流导致大规模的相干二级结构引起高振幅的空间和时间的温度变化。这些延伸的结构将显著改变运输。该项目将推进我们对液态金属和其他导电流体的磁流体动力学（MHD）流动中的传热和传质的理解。使用直接数值模拟和高保真实验室实验与汞相结合，我们计划调查对流不稳定性和二级结构的发展的情况下，当施加的磁场是强的，因此，预计将改变流动的性质。最后，我们将寻求控制流动的可能性，以抑制这种不稳定性，从而防止温度不均匀性。我们的德俄联合项目对聚变反应堆冷却和增殖液态金属层的设计有直接影响。预计该项目的成果将有助于为热核实验堆和演示实验开发试验包层模块，特别是用于开发双冷却剂包层和氦冷却包层。

The proposed project investigates the heat and mass transfer in liquid metals flows through rectangular ducts affected by strong magnetic fields. More specifically, the work explores the hypothesis that, in the conditions of complete turbulence suppression by the magnetic field, thermal convection leads to large-scale coherent secondary structures causing high-amplitude spatial and temporal variations of temperature. These extended structures will alter the transport significantly. The project will advance our understanding of heat and mass transfer in magnetohydrodynamic (MHD) flows of liquid metals and other electrically conducting fluids. Using combination of direct numerical simulations and high-fidelity laboratory experiments with mercury, we plan to investigate convection instabilities and development of secondary structures in the case when the imposed magnetic field is strong and, therefore, expected to change the nature of the flow. Finally, we will seek for the possibilities to control the flow in order to inhibit such instabilities and, therefore, to prevent temperature non-uniformities. Our joint German-Russian project has direct implications for design of cooling and breeding liquid metal blankets for fusion reactors. It is expected that the results of the project will assist the development of test blanket modules for the ITER and DEMO experiments, in particular for the development of dual-coolant and helium-cooled blankets.