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,获得一氧化氮带系(A2+ X2)对Te两条谱线214 nm和225 nm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''对新建的高焓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21.6 MPa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 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.
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