Measurements of fluctuating temperatures in a supersonic turbulent flow using laser-induced fluorescence

摘要: A laser-induced fluorescence technique that provides a practical means of nonintrusively measuring the instantaneous temperatures in low-temperature turbulent flows has been developed. It relies on from small concentrations NO flow N2. The demonstrated two-dimensional boundary layer at Mach 2. Both one and two-photon excitation methods were used, but limits imposed method by Stark effects rendered it less accurate. Single-pulse measurements, with 100 ppm NO, obtained range 150 to 295 K an uncertainty 1% rms. Fluctuations up 6% rms observed, owing flow. average temperature distribution through agreed well implied pitot-probe data.