Translational Temperature Distribution Measurements in High Enthalpy Flows by Laser-Induced Fluorescence

The translational temperature and the flow velocity distributions in high enthalpy flows are deduced with Two-photon Absorption Laser induced fluorescence diagnostics system to atomic oxygen. The laser line width and the center excitation wavelength are estimated by LIF profiles obtained from a flow reactor simultaneously. In this flow reactor, atomic oxygen is generated by microwave discharge. The number density of atomic oxygen in this flow reactor is estimated by titration with nitrogen dioxide. Compared with the LIF signal from the flow reactor set inside the measurement region, the number density distributions in Arc heated wind tunnel flow are obtained. From these results, enthalpy modal fractions are evaluated.