Experimental studies of the oscillatory combustion of hydrogen in a stirred flow reactor

Abstract

Experimental studies of the phase relations between H atoms, OH radicals and reactant temperature during the gas-phase, oscillatory combustion of hydrogen in a well-stirred flow reactor are reported. Absolute concentrations of the OH radical and the reactant temperature were measured in absorption from the vibrational-rotational structure of the laser-induced, electronically excited, OH spectrum . Relative concentrations of H atoms were obtained by multiphoton ionization, also induced by a laser. The hydrogen atoms reached their maximum concentration first during the oscillatory combustion, rising to a sharp peak followed by a rapid decay within several milliseconds. The OH radicals reached their maximum concentration about 1 ms after the H atoms. The maximum of the reactant temperature was in phase with the hydroxyl radicals. Experimental and numerical studies of the interaction that occurs between oscillations in a pair of coupled reactors are also presented.