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

研究的目的是研究高温高超声速流场中基本形状物体的绕流特性，获得作用在模型上的气动力，并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、半圆和卵形三种基本形状的物体暴露在为研究而设计的弧等离子体风洞的流动中，并用光谱测量的方法对流场进行了检测。用电子探针(EPMA)研究了黄铜和不锈钢模型的合金成分沿模型表面的变化。另一方面，制作了一个紧凑而廉价的力天平，用于测量等离子体流中基本形体的阻力，并推导了阻力系数。…驻点附近的温度根据Boltzman图的结果计算出更多的圆盘和半平面模型为3500K，略低于我们的预期，即4000K。在圆盘和半平面模型中，中性和电离的Ar原子沿停滞线的数密度在停滞点的前面急剧增加。然后，中性Ar原子的密度向停滞点方向降低，这与电离结果相反，因为停滞点附近的极高温度使中性Ar原子转化为电离Ar原子。而卵形圆柱体的数密度变化规律与无模型流动的结果基本一致，圆盘形体和半圆形体的合金成分变化与前表面的锌和铜的初始成分相反，即锌的含量增加，铜的含量增加。这可以从锌与铜相比的高扩散率和模型前方存在滞止的流场的角度来解释。研究还发现，在高焓流动情况下，这些模型的阻力系数可能比在无等离子体流动情况下的阻力系数小。它们的细节和原因应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的变分数据的一部分。较少

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