热电磁多场耦合下微槽道内液态金属流动及传热的机理研究

Controlled fusion is one of the most important ways to solve the problems of human energy and the environment. The interaction between plasma and wall is a fundamental scientific problem in nuclear fusion devices. The present research shows that due to the complexity of thermoelectric magnetic field coupling, up to now, it is not possible to provide accurate solutions to the mechanism of multi-field coupling and flow heat transfer control technology. In view of the above deficiencies, the project will carry out theoretical analysis, numerical simulation and experimental research. The micro channel structure of the plasma-oriented component under the coupling of thermoelectric magnetic field with full liquid film covering is developed. The project will analyze the micro channel liquid metal flow and heat transfer process under multi-field coupling of the large temperature difference, strong magnetic field and electric field and explore micro channel liquid metal flow instability mechanism under magnetic fluid dynamics effect and the Marangoni effect. The project will establish the heat transfer model relationship between the magnetic field intensity and direction, the magnitude and direction of the applied current, the micro channel structure and the attached insulating coating and heat transfer enhancement model in the micro channel with multi-field coupling. Through in-depth study, we will master the control methods and technical means of the unsteady flow and heat transfer of liquid metal in micro channel under thermo electromagnetic coupled environment, and provide a basis for the application of liquid metal in the plasma facing parts of fusion reactor.

受控核聚变是最终解决人类能源及环境问题的重要途径之一，等离子体和器壁之间的相互作用是核聚变装置中的一个关键科学问题。研究现状表明，由于热电磁多场耦合的复杂性，至今为止仍无法准确提供多场耦合下面向等离子体部件的稳定流动换热的解决方案和流动传热控制技术。本项目针对以上不足，系统地开展理论分析、数值模拟和实验研究，发展能够实现全液膜覆盖的热电磁多场耦合下的面向等离子体部件微槽道结构，分析大温差、强磁场和电场多场耦合下微槽道内液态金属流动及传热过程，探究强磁场作用下的磁流体动力学效应和马兰戈尼效应对微槽道内液态金属不稳定流动传热影响机理，建立在多场耦合情况下包括磁场强度和方向、外加电流大小和方向、微槽道结构和附着绝缘涂层的微槽道内液态金属传热模型和换热增强关系。通过深入研究掌握热电磁多场耦合下微槽道内液态金属不稳定流动换热的控制方法与技术手段，为液态金属在聚变堆面向等离子体部件的应用提供基础。

本项目围绕热电磁多场耦合下微槽道内液态金属流动及传热的机理开展研究，分析了多场耦合下液态金属受强磁场和电场影响下的流动特征和换热规律。受控核聚变是最终解决人类能源及环境问题的重要途径之一，等离子体和器壁之间的相互作用是核聚变装置中的一个关键科学问题，本项目围绕等离子体和器壁之间的相互作用的液态金属膜流，系统地开展了理论分析、数值模拟和实验研究，获得了主要影响因素，包括不同的磁场大小、电流大小、温度梯度、微槽道结构对 MHD 效应和 Marangoni 效应耦合情况下微槽道内液态金属流动和传热规律。研究表明平均努塞尔数与哈特曼数之间呈幂指数关系，并且平均努塞尔数随哈特曼数增大会而减小，表明磁场对液态金属膜流的流动与换热具有抑制效应。液态金属的微槽道膜流实验证明微槽道表面有助于实现液态金属的均匀铺展与稳定流动，多场耦合下磁场会增大液态金属的流动阻力，当磁场强度较小时，液膜后端区域的波动随着磁场强度增大而增大，波纹形状愈发规则，磁场强度较大时液膜后端区域由大幅度的波动状态转变为平稳流动，中间区域由杂乱无章的小波动状态转变为规则的大幅度波动。强磁场下方管微槽道表面提高了液态金属与加热板之间的对流换热效率，微槽道增加了换热面积，磁场强度增大导致了液态金属射流越强，射流增加增强了液态金属与微槽道加热壁面之间的平均换热努塞尔数。通过本项目，掌握了热电磁多场耦合下微槽道内液态金属流动换热增强控制方法与技术手段，实现了全液膜覆盖的热电磁多场耦合下的面向等离子体部件微槽道结构下稳定流动的探索性研究，为液态金属在聚变堆面向等离子体部件应用和相关工业过程提供了基础。