高焓风洞自由流中一氧化氮含量的诊断

介绍ＪＦ－１０氢氧爆轰驱动激波风洞自由流中ＮＯ的诊断技术及其实验结果．这里使用的是新研制的紫外波段的动态吸收光谱测量系统．该系统以Ｔｅ元素空心阴极灯为光源，以ＯＭＡＩＶ为探测设备，通过标定，获得一氧化氮 γ带系　　　对 Ｔｅ两条谱线２１４ｎｍ和 ２２５ｎｍ的吸收特性，得到在 ＮＯ低含量时对两条谱线的吸收系数差别很大并呈非线性的特点．利用这两条谱线吸收系数的差值，用“差比法”对新建的高烙爆轰驱动激波风洞中自由流 ＮＯ含量进行了诊断．实验结果表明，在总温 ８５００ Ｋ、总压２１．６ＭＰａ时ＮＯ含量甚微，小于 ４×１０１４分子／ｃｍ３．这一结果说明该风洞自由流处于化学准平衡状态．

THE NITRIC OXIDE CONCENTRatION DIAGNOSTICS IN FUSE STREAM OF A HIGH ENTHALPY SHOCK TUNNEL

The paper is concerned with ultraviolet absorptive spectroscopymeasurement system for concentration measurement of nitric oxide in freestream of a high enthalpy shock tunnel and test result. Our systememploys Te hollow cathode lamp as light source and OMAIV as detectiondevice. The absorptive properties of NO band (A2+X2 transition) versus selected lines of Te HCL (214 nm and225 nm) are measured on static condition. The static investigationshows that difference between two absorptive coefficients isremarkable and nonlinear when the density of nitric oxide is less than2.4210-4kg/m3.The scheme is used to process data whichwere acquired during operation of JF-10 shock tunnel and concentrationof nitric oxide in free stream is determined. The concentration ofnitric oxide in free stream is less than 4.0 1014molecular/cm3 when total temperature is 8500 K and total pressure is21.6 MPa. It is concluded that property of free stream can satisfyfuture real gas effect simulation test.