Development of measuring systems of dissociated oxygen in hypersonic tunnel flows

高超声速风洞流动可以为包括HOPE-X和即将到来的命名航天飞机项目在内的整个日本空间项目提供支持的数据库。特别是，为了解决再入空间飞行器的热屏蔽问题，必须对现有的激波管进行升级，以满足这些极端条件的产生。本研究的目的是开发设备和测量系统。(1)将100 mm×180 mm激波管的高压室改造为爆轰驱动操作系统，并采用快开阀，以保证较高的重复性。从数值和实验上阐明了其特性。(2)对爆轰波的起爆进行了实验研究。在爆震室中激光点燃了质量从1.0到10 mg的微装药，以阐明从爆燃驱动冲击波到爆轰的转变，在初始压力从10到100kPa的氢氧米塔管中。通过全息干涉观测，确定了起爆边界。(3)对二维喷管和轴对称喷管的起爆过程进行了数值模拟和实验研究。在轴对称喷嘴的情况下，构造了一个非球面透镜形状的会聚发散喷嘴，准直的物光束可以通过而不会对测试截面的图像造成任何失真，从而实现了图像数据的定量采集。(4)为了解释实验结果，提出了一种非结构网格的Dinette差分格式，并获得了较高的分辨率。

Hypersonic wind tunnel flows can provide data base which would support entire Japanese space projects including HOPE-X and forth coming named space shuttle projects. In particular, to resolve heat shielding of re-entry space vehicles, the existing shock tube has to be upgraded to satisfy the generation of these extreme conditions.The aim of the present study is to develop the facility and measuring systems. Results obtained are summarized as following :(1) The high pressure chamber of a 100 mm x 180 mm shock tube has been modified to detonation driving operation systems and a quickly opening valve has been adopted to ensure higher degree of repeatability. Its characteristics are numerically and experimentally clarified.(2) The initiation of detonation waves was experimentally examined. A micro-charge ranging from 1.0 to 10 mg in weight was laser ignited in a detonation chamber, in order to clarify the transition from deflagration driven shock waves to detonation, in oxyhydrogen miters at initial pressure from 10 to 100 kPa. By using holographic interferometric observations, the boundary of initiations has been determined.(3)Starting processes in two-dimensional and axisymmetric nozzles have been numerically and experimentally investigated. In the case of an axisymmetric nozzle, an aspheric lens shaped converging and diverging nozzle was constructed and collimated object beam could pass without creating any distortion of images of test section, with which a quantitative image data acquisition became possible.(4) For the interpretation of experimental results, a dinette difference scheme using unstructured grids has been developed and a higher resolution has been obtained.