Effect of Flame Inhibitors on Detonation Characteristics of Fuel-Air Mixtures

Abstract

Propagation of flames and detonation waves in fuelair mixtures with inhibitor additives is studied. Propane and hydrogen are chosen as fuels and tetrafluorodibrorooethane as an inhibitor. Experiments are performed in a tube. The detonation and flammability limits are determined as functions of the inhibitor concentration in the mixture. For propane-air mixtures the additive decreases the detonation velocity beyond the value characteristic of detonation limits of noninhibited mix* tures.The flammability limits narrow faster than the detonability limits as the inhibitor concentration grows, so that detonation propagates in mixtures that can not support flame, / I n inhibited hydrogen-air mix tures detonation limits are narrower than the flammability limits. A comparison of the calculated and measured detonation velocities reveals that the inhibitor additives enhance to some extent the heat release !behind the detonation wave. For hydrogen-air mixtures the measured velocities exceed the calculated ones at Copyright © 1992 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. *Head of Laboratory, N. Semenov Institute of Chemical Physics. fGraduatc Student, Moscow Physical Engineering Institute, t Junior Researcher, N. Semenov Institute of Chemical Physics. §Engineer, Moscow Physical Engineering Institute. fSenior Researcher, N. Semenov Institute of Chemical Physics.