Comparison of rotational and vibrational thermometry of detonation in microchannels

Vibrational and rotational temperatures in various detonation conditions involving diluted hydrogen-oxygen mixtures were studied in a microscale detonation tube using hybrid fem- tosecond/picosecond Coherent anti-Stokes Raman scattering (hybrid fs/ps CARS). Measured temperatures at various locations behind the shockwave were compared to Chapman-Jouguet conditions as predicted by equilibrium calculations. Simultaneous shadowgraphy was also employed to establish timing between the detonation wave and laser beams. Comparison between vibrational nitrogen and oxygen thermometry were made for detonations in the same gas mixture. Oxygen rotational temperature was measured and compared to vibrational temperature measured in a similar gas mixture.