"Advanced Application of Gas-dynamic to Planetary Exploration"

对气体动力学在未来行星探测中的应用进行了广泛的研究，主要集中在计划用于缪斯-C任务的返回舱。ISAS计划的缪斯-C任务是与一颗小行星会合，并将其土壤带回地球。由于其再入速度较高(-13公里/秒)，各种气体动力学问题亟待解决。本文主要研究了以下几个方面的问题：1)飞行器前方高温激波层的辐射效率估算；2)高温空气与飞行器隔热罩材料的相互作用；3)高度非平衡高温激波层引起的气动热流密度估算。其中一个主要的主题是实验上观察到的高度热非平衡现象。这一结果有望对改进现有的流动模型产生一定的影响，并有助于提高改进后的流动模型的估算精度。综合各课题的计算结果，成功地估算了再入飞行器飞行轨迹上的气动加热，为此类飞行器的设计提供了依据。同时，对这种再入飞行器进行飞行演示的可能性进行了研究。除了再入飞行器之外，还研究了穿透系统在未来行星解释中的应用。从气体动力学的角度，这一系统研究成功地阐明了这种穿透系统的设计要求。此外，还对RAM加速器系统进行了研究，为月球探测成果的传输奠定了基础。即使在实验室规模上，RAM加速器也得到了成功的演示。

The extensive research was made on application of gas-dynamics on the future planetary exploration, mainly focusing on the reentry capsule which is planned for MUSES-C mission. MUSES-C mission planned by ISAS is to have a rendezvous with an asteroid and to bring back its soil to Earth. Since its reentry speed is quite high (-l3 km/sec), a variety of gas-dynamical problem must be resolved.In the present research, research effort was focused on the following main problems ; 1) the radiation efficient estimation from high temperature shock layer ahead of the vehicle, 2) the interaction of the high temperature air with the heat shield material of the vehicle, 3) the estimation of aerodynamic heat flux caused by highly-nonequilibrium high temperature shock layer. One of the main topics is the highly thermally-nonequilibrium phenomena, which is observed experimentally. This result is expected to have an impact on improving the current flow model, and to be helpful to improve the estimation accuracy by the improved flow model. Combining the results obtained from various topics, the aerodynamic heating along the flight path was successfully estimated, which was helpful to make a design requirement for such a reentry vehicle. In parallel, the possibility of the flight demonstration of such a reentry vehicle was studied.Other than the reentry vehicle, a study was conducted on the use of penetrator system for future planetary explanation, in a gas-dynamical point of view, This system study successfully clarified a design requirement of such a penetrator system. Also, the RAM accelerator system was studied, which is useful for the transportation of the exploration result from Moon. Even in a laboratory scale, the RAM accelerator was successfully demonstrated.