Experimental investigation of coupled MHD and thermal radiation effects in Rayleigh-Bénard Convection

Rayleigh-Bénard对流（RBC）一直是流体流动与传热领域的经典课题。随着科学技术的发展和进步，以及学科间的交叉融合，经过一百多年的研究，RBC出现了新的内容和挑战。例如，在新兴的可再生能源研究领域和传统的航空航天领域，电磁场和/或热辐射对流体流动和传热的影响已经不能被忽视。本研究计划旨在开展热辐射和电磁场联合作用下红细胞内流体流动和传热的基础实验研究。拟议的模型实验应得到相应的数值模拟的支持，这些数值模拟不在本提案的供资范围内。在此，将进一步开发在磁场影响下RBC的现有和经验证的内部代码，以包括热辐射的影响。系统的基础研究，其特点是导电流体和高温的操作，尚未进行。根据工作经验和现有的实验基础设施，实验研究将集中在高达600 K的温度范围和高达5 T的强外部磁场的影响。在本研究计划的框架内，将与大连理工大学中文系李本文教授建立非正式合作关系。在大连，重点将是研究在没有磁场的情况下，远超过600 K的高温辐射效应。系统地揭示了传热与流体流动的精确关系，即Nusselt数和Reynolds数对控制参数Rayleigh数（热驱动）、Planck数（热辐射）和Hartmann数（磁场）的依赖关系。此外，流体流动从经典区到极限区的转变的可能性将被探索与临界参数一起。结合工程应用，分析了高温储热系统和液态金属电池的不稳定性，并提出了抑制不稳定性的技术措施。

Rayleigh-Bénard Convection (RBC) has been being a classical topic in the area of fluid flow and heat transfer. With the development and progress of science and technology, as well as the cross accommodation of disciplines, new contents and challenges appear in the RBC even after more than one hundred years’ researching. For instance, in the newly arising area of renewable energy research and the traditional aerospace area, the influences of electromagnetic field and/or thermal radiation on fluid flow and heat transfer cannot be ignored anymore. The present research proposal aims to conduct fundamental experimental research of fluid flow and heat transfer in RBC influenced by the combined effects of thermal radiation and electromagnetic fields. The proposed model experiments shall be supported by respective numerical simulations that are no subject for funding within the present proposal. Here, already available and validated in-house codes for RBC under the influence of magnetic fields will be further developed to include the effects of thermal radiation. Systematic fundamental studies in systems, characterized by electrically conducting fluids and high temperatures of operation, have not been performed yet. According to the working experience and the already existing experimental infrastructure the experimental investigations will focus on the temperature range up to 600 K and on the influence of strong external magnet fields up to 5 T. In the frame the present research proposal, an informal cooperation with Prof. Benwen Li of Dalian University of Technology Chinese will be established. At Dalian, the focus will be on the study of high-temperature radiation effects well beyond 600 K in the case when magnetic fields are absent. The precise relations of heat transfer and fluid flow, i.e. the dependence of Nusselt number and Reynolds number on the control parameters Rayleigh number (thermal driving), Planck number (thermal radiation) and Hartmann number (magnetic field) will be systematically revealed. Moreover, the possibility of fluid flow transformation from classical regime to ultimate regime will be explored together with the critical parameters. Combining with engineering applications, the instabilities in high-temperature thermal storage systems and liquid metal batteries will be analyzed, and techniques will be proposed to suppress them.