CONTINUOUS-WAVE DYE-LASER TECHNIQUE FOR SIMULTANEOUS, SPATIALLY-RESOLVED MEASUREMENTS OF TEMPERATURE, PRESSURE, AND VELOCITY OF NO IN AN UNDEREXPANDED FREE JET
CONTINUOUS-WAVE DYE-LASER TECHNIQUE FOR SIMULTANEOUS, SPATIALLY-RESOLVED MEASUREMENTS OF TEMPERATURE, PRESSURE, AND VELOCITY OF NO IN AN UNDEREXPANDED FREE JET
复制标题
DOI：
10.1364/ao.32.004074
复制
发表时间：
1993-07-20
期刊：
影响因子：
1.9
通讯作者：
HANSON, RK
中科院分区：
文献类型：
--
作者：
DIROSA, MD;CHANG, AY;HANSON, RK
利用腔内倍频、快速调谐的连续环形染料激光器，非侵入性地测量了注入0.5%NO的欠膨胀无氮喷流内的气体动力学参数。紫外光倾斜地穿过喷流轴，其频率以4 kHz的速率在225 nm附近的NO伽马带内重复扫描相邻的旋转线。通过监测诱导的宽带荧光获得空间分辨的激发扫描。利用Voigt曲线对多普勒频移激励扫描进行建模，可以同时确定无速度、旋转温度和压力。零多普勒频移是指在静态池中获得并与激发扫描同时记录的吸收轨迹。通常情况下，测量和预测的轴向分布在10%以内。当马赫数较高时，有证据表明NO发生了旋转冻结。
Gas dynamic quantities within an underexpanded nitrogen free jet, seeded with 0.5% NO, were measured nonintrusively by using an intracavity-doubled, rapid-tuning, cw ring dye laser. The UV beam passed obliquely through the jet axis, and its frequency repetitively scanned across adjacent rotational lines in the NO gamma band near 225 nm at a rate of 4 kHz. Spatially resolved excitation scans were obtained by monitoring the induced broadband fluoresence. Modeling the Doppler-shifted excitation scans with Voigt profiles permitted simultaneous determinations of NO velocity, rotational temperature, and pressure. Zero Doppler shift was referenced to an absorption trace obtained across a static cell and recorded concurrently with the excitation scan. Typically, the measured and predicted axial distributions agreed within 10%. At high Mach numbers there was evidence of rotational freezing of NO.