高温超声速磁流体发电的近电极热电磁流动机理研究

Magnetohydrodynamic (MHD) power generation has important application prospects in hypersonic vehicle, and its engineering application will certainly bring about a revolutionary progress. At present, the possibility analysis has been made by many researchers, and great progress has also been achieved on principle verification experiments. However, there are still some basic subjects need to be studied, such as the influence of parameter variation on conductivity, spatial distribution model and thermal-electromagnetic-flow characteristics near electrode. Based on the preliminary investigation, this project is mainly focused on the spatial distribution model and thermal-electromagnetic-flow characteristics near electrode. Under typical experiment, the conductivity of flow will be tested, and the influence of parameter variation will also be obtained. Spatial distribution model will be acquired through theoretical analysis, and then it will be used for MHD simulation research, at last the simulation results are verified by experiment. The near electrode thermal-electromagnetic-flow characteristics are acquired through experiment, simulation and theoretical analysis, and multi-field coupling mechanism is revealed. This project research will be useful for understanding the mechanism of high temperature ionization, and recognizing the complex flow phenomenon of MHD power generation channel，which is believed to underpinned the application of MHD power generation on hypersonic vehicle.

磁流体发电技术在高超声速飞行器上有着广泛的应用前景，其工程应用将给高超声速飞行器性能带来一次革命性的提高。目前，国际上已经对磁流体发电技术应用的可行性进行了分析，原理性验证实验也取得了快速进展，但对导电流体电导率参数变化影响规律、空间分布模型以及近电极热电磁流动特性等基础问题尚不清楚。本项目在初步研究的基础上，围绕电导率空间分布模型及近电极热电磁多场耦合机理两个科学问题开展研究。典型实验条件下对导电流体电导率进行测试，并获得参数变化的影响规律，通过理论分析得到电导率空间分布模型；利用研究得到的模型作为计算条件，开展磁流体发电数值模拟研究，并通过实验对数值模拟结果进行验证，实验研究、数值模拟和理论分析结合，研究得到磁流体发电近电极热电磁流动特性，揭示多场耦合机理。以此，深化对高温燃气电离机理的理解，提高对磁流体发电通道内部复杂流动现象的认识，为磁流体发电技术在高超声速飞行器上的应用提供支持。

磁流体发电技术在高超声速飞行器上有着广泛的应用前景，其工程应用将给高超声速飞行器性能带来一次革命性的提高。目前国际上对导电流体电导率参数变化影响规律、空间分布模型以及近电极热电磁流动特性等基础问题尚不清楚。本项目研究可为磁流体发电技术的应用提供必要的理论基础和技术支撑。.发展了实验设备和实验技术，研制了磁流体发电实验系统，实现导电流体的产生。采用煤油和气氧作为燃料和氧化剂，混合比2.1，燃烧室压力0.7MPa，通过实验调试确定了系统的运行时序，进行了运行时间为3s的高温实验，燃烧温度最高达3278.5K。提出了热沉式磁流体发电通道设计思路，通过传热理论分析了热沉式发电通道的可行性，研制的发电通道在温度2800K、马赫数1.5的工况下稳定工作5s。运用多相流仿真分析了固态电离种子注入方法的注入效果；选用溶解式电离种子注入方法，种子与燃气的掺混效果较好，当加入过量电离种子时，电导率不增反降。通过对比实验，确定了试验工况下燃气行程约为300mm。在温度2800K，种子比1.5%时，最大电导率测量值为26.1S/m。研究了燃气行程、燃气温度、种子比三个因素对燃气热电离的影响，燃气温度是影响燃气热电离过程的主要因素，根据电导率测量值拟合了电导率温度模型。.基于低磁雷诺数假设的磁流体五方程模型，针对分段法拉第型磁流体发电通道，结合实验参数，数值模拟研究了通道内流场和近电极热电磁流动情况，获得了发电通道内部流动情况和能量转化参数变化规律，磁作用数越大，通道出口温度越高，通道能量转化率越高；增大电磁作用强度，选择合适的外部负载，可以提高通道发电性能。进行了连续法拉第型磁流体发电实验，种子比1.5%，燃气温度2800K，外部负载150Ω，最大输出电压58V，电流0.43A，最大输出功率为24.94W，功率密度0.28MW/m3。揭示了影响磁流体发电性能的物理机制主要是电极压降、电极纵向漏电损失及焦耳热耗散。.已发表或录用期刊论文10篇，其中，SCI收录1篇，EI收录9篇；发表国内外会议论文8篇；申请国防发明专利3项；培养毕业硕士研究生2名。