Kinetic Studies of Plasma Chemical Fuel Oxidation in Nanosecond Pulsed Discharges by Single and Two Photon Laser Induced Fluorescence.

摘要

Single and two photon Laser Induced Fluorescence (LIF) spectroscopy is used for measurements of the hydroxyl radical (OH) and atomic oxygen number densities, respectively, in nanosecond pulsed nonequilibrium discharges. In the case of OH LIF rotational temperatures are also obtained, which are found to agree well with temperatures inferred from Coherent Anti-Stokes Raman Spectroscopy (CARS). The temporal evolution of OH and temperature after application of a burst of 50 nsec pulses at 10 kHz repetition rate in fuel lean hydrogen, methane, ethylene, and propane-air plasmas at P = 100 Torr is compared to predictions from a plasma-chemical fuel oxidation code. It is found that the kinetic mechanisms developed by A. Konnov provide the best overall agreement with the experimental data. Atomic oxygen data in 40 Torr hydrogen- air mixtures indicates significant low temperature chemical oxidation.