NO激光诱导荧光对高焓气流温度的测量

由于真实气体效应，高超声速流场的研究仍然依赖于大量的实验.流场温度是实验的重要参数，目前只能通过具有非入侵性质的光学测量手段获得，然而，由于多方面的难题，鲜有对高焓流场参数测量的报道.文章介绍了利用激光诱导荧光（laser-induced fluorescence，LIF）技术对JF-10氢氧爆轰激波风洞产生的高焓实验气流温度的测量工作.搭建了用于脉冲式风洞的LIF测量系统，使用了NO分子作为荧光组分.因为高焓流场实验条件苛刻，本实验对传统的激光设置进行了调整，使用了平行于拍摄方向的竖直平面激光激发NO，使荧光信号更为集中，获得了清晰的LIF图像.利用双线测温法（two-line thermometry，TLT）测量高焓自由流中NO分子的转动温度，从而确定气流的平转温度.测量结果表明，JF-10实验气流的平转温度为600 K. 

Temperature Measurement in High-Enthalpy Flow by NO Laser-Induced Fluorescence

Due to real-gas effect,the studies of hypersonic phenomena still rely on experiments.Temperature,one of the key parameters of the flow-field,can only be acquired by optical diagnostics.However,as there are challenges from many aspects,few works regarding measurements in high-enthalpy flow have been reported.This paper presented the laser-induced fluorescence(LIF)investigation of high-enthalpy flow generated by JF-10,a H 2/O 2-detonation-driven shock tunnel.A LIF system was established for the impulsive testing facility,and nitric oxide(NO)was chosen as the fluorescent species.Since the testing environment is harsh for LIF measurement,adjustments have been made on the conventional planar LIF technique.The excitation planar beam was made parallel to the direction of the detector,thus the fluorescence signal was concentrated,and clear LIF images were taken.By two-line thermometry(TLT),the rotational temperature of NO molecules in the free stream at the test section was acquired,and thus the translational and rotational temperature of the flow was determined.The result shows that the translational and rotational temperature of the test flow is 600 K.