Simultaneous spatially resolved temperature, pressure, and velocity measurements in high-enthalpy gas environments using spectrally resolved laser-induced fluorescence of potassium vapor
摘要
A novel, absorption lineshape-based, laser-induced fluorescence diagnostic has been developed for simultaneous, single-point measurements of temperature, pressure, and velocity in high-enthalpy flow environments. The technique uses wavelength-tuned, narrow-linewidth, continuous-wave lasers to excite atomic potassium vapor, which is used as a flow tracer. The laser pumps the potassium D2 electronic transition, near 766.7 nm, while fluorescence from both the D1 and D2 lines is monitored simultaneously. The technique uses spectral lineshape and line position for inferring flow field properties, eliminating the need for detailed, setup-dependent calibration factors for quantitative measurements. The technique was tested and validated in argon and nitrogen in a shock tube with temperatures, pressures, and velocities ranging from 1000-2600 K, 0.1