Experimental investigation of superstructures in turbulent liquid metal convection

液态金属湍流对流上部结构的实验研究

• 批准号: 428906173
• 负责人: Dr.-Ing. Tobias Vogt
• 金额: --
• 依托单位: Abteilung Magnetohydrodynamik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/428906173?language=en
• 关键词: Experimental; investigation; superstructures; turbulent; liquid

The appearance of thermal superstructures in turbulent convection within very low Prandtl number fluids will be investigated experimentally in a large aspect ratio domain. The experiments will be conducted using the liquid metal Gallium-Indium-Tin (GaInSn) that has a Prandtl number of Pr ≈ 0.03. Combined temperature and velocity measurements will provide detailed information about turbulent, convective superstructures and their dynamics. A novel Ultrasound-Doppler-Array technique will be used to measure for the first time two dimensional velocity vector fields of the superstructures in a turbulent liquid metal convection. The velocity measurements are complemented by simultaneous temperature measurements at up to 100 measuring positions to enable spatio-temporal mapping of the temperature distribution in the thermal boundary layer. High-frequency sampling of the velocity and temperature field at local positions will be performed to obtain turbulent statistics while long time measurements over ten thousands of convective freefall time units will reveal the long-term dynamics of the flow pattern. Besides that, we will provide scalings for the heat and momentum transport. The proposed experiments will set a new milestone for a deeper understanding of turbulent superstructures at very low Prandtl numbers with regard to their major relevance both in geo- and astrophysical flows as well as in engineering systems.

将在大纵横比域中对极低普朗特数流体内的湍流对流中热上层结构的出现进行实验研究。实验将使用普朗特数为 Pr ≈ 的液态金属镓-铟-锡 (GaInSn) 进行。 0.03。结合温度和速度测量将提供有关湍流、对流上层结构及其动力学的详细信息。超声波多普勒阵列技术将首次用于测量湍流液态金属对流中上部结构的二维速度矢量场。速度测量辅以最多 100 个测量位置的同步温度测量，以实现时空测量。绘制热边界层温度分布图，对局部位置的速度和温度场进行高频采样，以获得湍流统计数据，同时进行数万个对流自由落体时间的长时间测量。除此之外，我们还将提供热和动量传输的尺度，为更深入地了解普朗特数极低的湍流上层结构奠定了新的里程碑。它们在地球和天体物理流以及工程系统中具有重要意义。