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.

我们将在大长宽比范围内对极低普朗特数流体内湍流对流中热超结构的出现进行实验研究。实验将使用Prandtl数为Pr≈0.03的液态金属镓铟锡(GaInSn)进行。温度和速度的联合测量将提供关于湍流、对流超结构及其动力学的详细信息。一种新的超声-多普勒阵技术将首次用于测量湍流液态金属对流中超结构的二维速度矢量场。除了速度测量，还有多达100个测量位置的同步温度测量，以便能够绘制热边界层中温度分布的时空图。对局部位置的速度场和温度场进行高频采样，以获得湍流统计数据，而超过1万个对流自由落体时间单位的长期测量将揭示流型的长期动力学。除此之外，我们还将提供热量和动量传输的定标。拟议的实验将为更深入地理解普朗特数很低的湍流超结构树立一个新的里程碑，因为它们在地球物理和天体物理流动以及工程系统中都具有重要意义。