An Application of Laser-Raman-Spectroscopy to Thermochemical Measurements in an Arc-Heated Wind Tunnel Flow

摘要

Laser Raman Scattering (LRS) has been investigated as a possible approach toward providing a nonperturbing flow calibration method for arc-heated wind tunnel facilities. Such a calibration is needed to evaluate the chemical and thermodynamic properties of the high temperature air flow which cannot be accurately determined using standard probe techniques. Theoretical calculations showed that the number densities and vibrational temperatures of nitrogen, oxygen, and nitric oxide could be obtained using the Raman spectroscopic method. Exploratory experimental LRS results obtained in the Air Force Flight Dynamics Laboratory 50-Megawatt Reentry Nose Tip (RENT) Facility showed that it is indeed feasible to apply LRS to arch-tunnel flow diagnostics. (Author)