High Temperature Hypersonic Flow Field Around Basic-Shape Biodies and The Metal Component Alterationin

研究高温高超声速流场中基形体的流动特性，获得作用在模型上的气动力，研究高温对模型金属成分的影响，以开发新材料或处理注射针等难处理材料。将圆盘形、半球形和椭圆形三种基本形状的物体暴露在电弧等离子体风洞的气流中，并通过光谱测量对其流场进行了研究。利用电子探针微量分析仪（EPMA）沿模型表面分析了黄铜和不锈钢模型的合金成分变化。另一方面，制作了一种紧凑、廉价的力天平来测量等离子体流中基形体的阻力，并推导出阻力系数。根据玻尔兹曼图的计算结果，更多的圆盘和半球模型的滞止点附近的温度为3500 K，比我们预期的4000 K略低。在圆盘和半球模型中，沿滞止线的中性氩原子和电离氩原子的密度在滞止点前急剧增加。然后，中性氩原子的密度向驻点方向下降，与电离结果相反，这是由于驻点附近的极高温度使中性氩原子转变为电离氩原子。另一方面，在滞止点上游，ogive圆柱体的数密度变化几乎是恒定的，这与无模型流动的结果相似。圆盘和半球体的合金成分变化与最初正面锌和铜的成分呈反比，即锌增加，铜反之。这可以从锌相对于铜的高扩散率和模型前流场存在滞止的角度来解释。这些模型在高焓流情况下的阻力系数可能小于无等离子体流情况下的阻力系数。他们的细节和原因应该在下一阶段的研究中进行调查。此外，这些数据将在不久的将来成为数值模拟程序验证数据的一部分。少

The objectives of the research are to study flow characteristics around a basic-shape body in high temperature hypersonic flow field, to obtain the aerodynamic force acted on the model, and to investigate the metal component alteration of the model owing to the high temperature for developing new materials or disposal of such a difficult-treatment material as an injection needle. Three type of basic-shape bodies, a disc, a hemisophere and an ogive cylinder were exposed to the flow of the arc-plasma wind tunncl which was made for the research, and the flow fields were examined by a spectroscopic measeurement. The alloy ingredient alteration of the models made by brass or stainless steel were also investigated by an electron probe microanalyzer (EPMA) along the model surface. On the other hand, a compact inexpensive force balance was made to measure the drag of the basic-shape bodies in the plasma flow and the drag coeflients were deduced.The temperature near the stagnation point of the … More disc and hemisophere models were calculated to be 3,500 K from the results of the Boltzman plots, which is a little bit lower than that we expected, that is 4,000 K.The number densities of the neutral and ionized argon atoms along the stagnation line in the cases of the disc and hemisophere models were drastically increased just in the front of the stagnation point. Then, the densities of the neutral argon atoms decreased towards the stagnation point on the contrary to the ionized results, since the neutral argons were converted to ionized ones due to extreamely high temperature near the stagnation point. On the other hand, the variation of the number density of the ogive cylinder was almost constant upstream of the stagnation point simillar to the result of the no-model flow.The alloy ingredient alteration of the disc and hemisophere bodies were inversely changed from the initial component of zinc and copper on the front-side surface, that is zinc was increased and vice versa for copper. It could be explained from the point of the high diffusivity of zinc compared with copper and the flow field in front of the models with the existence of the stagnation. It was also found that the drag coefficients for these models in the case of the high enthalpy flow might be smaller than those in the no-plasma flow case. Their details and the reason should be investigated in the next stage research. Farthermore, these data mentioned above will take a part in the varidation data for numerical simulation programs in near future. Less