Control of weakly ionized flow around a reentry vehicle and aerodynamic heating by means of electromagnetic effect

从太空再入飞行器面临的最大挑战是如何控制飞行器周围的高温气流，防止飞行器升温。传统上，控制是通过热保护系统进行被动管理的。相反，在本研究中，我们考虑了利用电磁效应进行主动控制，并从实验和数值两个方面探讨了其可行性。在实验中，研究了弧射流风洞中磁化体的绕流行为。为此，利用吸收光谱测量了平移温度的空间分布，并发展了一种新的方法，使我们即使在强磁场环境下也能应用吸收光谱。结果表明，与理论预测的结果一致，磁场对激波层有一定的强化作用。这一结果为开展对该现象的数值分析奠定了良好的基础，也为相关的研究工作做出了重要贡献。仿真结果与实验结果吻合较好。通过数值模拟发现，车辆表面对电磁效应有显著影响，并得到了实验验证。也证实了电磁效应在飞行条件下是有效的。阐明了电磁效应的基本现象及其在再入飞行器上应用的可行性。

The biggest challenge for a reentry vehicle from space is how to control the high temperature gas flow around the vehicle to prevent its heating-up. Traditionally, the control was passively managed by means of he heat protection system. On the contrary, we consider, in the present study, the active control by using the electro-magnetic effect and investigate its feasibility both experimentally and numerically. In the experiment, the flow behavior around the magnetized body set in the arc-jet wind tunnel was investigated. For this purpose, the translational temperature spatial distribution was measured by means of the absorption spectroscopy for which a new method was developed, which enables us to apply the absorption spectroscopy even in a strong magnetic field environment. The result shows the shock layer enhancement due to the magnetic field application, as the theory predicted. The present result gives a sound basis to develop the numerical analysis of the present phenomenon, and gives a significant contribution for the relevant investigation.The numerical simulation was developed for the present electromagnetic effect. The simulation result which shows a reasonable agreement with the present experimental result. It was found though the numerical simulation that the vehicle surface has a significant effect on the elelectromagnetic effect, which was experimentally confirmed. It is also confirmed that the electomagnetic effect is effective in a flight condition. In addition, the feasibility of the flight demonstration of the present method was revealed.The present study clarified the basic phenomenon of the electromagenetic effect and its feasibility of the application to the reentry vehicle.