Next step towards high-fidelity numerical simulations of turbulent heat transfer toliquid metals: forced and mixed convection with non-uniform wall heat flux, conjugate heat transfer and temperature dependent thermophysical properties

液态金属湍流传热高保真数值模拟的下一步：具有非均匀壁热通量的强制对流和混合对流、共轭传热和温度相关的热物理特性

• 批准号: 462658330
• 负责人: Professorin Dr.-Ing. Bettina Frohnapfel
• 金额: --
• 依托单位: Institut für Thermische Verfahrenstechnik (TVT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/462658330?language=en
• 关键词: Next; step; towards; fidelity; numerical

Liquid Metals (LMs) are promising candidates for Heat Transfer Fluids (HTFs) in applications where high heat flux densities and medium to high temperatures are present. The underlying physical heat transfer mechanism is strongly influenced by the high thermal conductivity of LMs and is substantially different from HTFs like air and water.Even though the application of LMs as HTFs show the potential of increasing the efficiency there is a lack of high-fidelity data on the turbulent heat transfer of LMs. In order to improve the understanding of the involved physical processes, an extended, thorough numerical analysis is proposed herein.Based on previous work on non-uniform thermal boundary conditions for forced convection, the next steps are to add the effects of buoyancy forces (mixed convection) as well as heat conduction within the solid part of the heat exchanger (conjugate heat transfer) and the temperature dependency of thermo-physical properties.The high-fidelity numerical simulations will be performed by the massively-parallelized, high-order, open source code Nek5000, which has been extensively tested, validated and shown to yield accurate results in the previous work.LM at two different Prandtl numbers, encompassing e.g. lead-bismuth eutectic (LBE) and sodium (Na), are to be studied over a range of range of parameters covering different regimes in opposed and aided mixed convection as well as different hydrodynamic operating conditions. The results of this study provide information to which extend the investigated phenomena influence heat transfer in LM. They provide essential reference data valuable for testing and tuning as well as improving models for turbulent heat transfer in LMs.

液态金属(LMS)在高热流密度和中高温的应用中是很有前途的传热液(HTF)候选材料。LMS的物理换热机理受其高导热系数的影响较大，与空气、水等热传导材料有很大的不同。尽管LMS作为热传导材料具有提高效率的潜力，但目前还缺乏关于LMS湍流换热的高保真数据。为了更好地理解所涉及的物理过程，本文提出了一种扩展的、全面的数值分析。在前人关于强迫对流的非均匀热边界条件的工作的基础上，下一步是增加浮力(混合对流)以及换热器固体部分内的热传导(共轭换热)的影响以及热物性的温度依赖性。高保真的数值模拟将使用大规模并行的高阶开放源代码Nek5000进行，该程序已经在两个不同的Prandtl数下得到了广泛的测试和验证，并得到了准确的结果。将对包括铅-铋共晶(LBE)和钠(Na)在内的一系列参数进行研究，这些参数涵盖了反向和辅助混合对流中的不同状态以及不同的流体动力操作条件。本研究的结果为所研究的现象对传热学的影响程度提供了信息。它们提供了重要的参考数据，对测试和调整以及改进LMS中的湍流换热模型很有价值。