Experimental Investigations of Acoustic-Kinetic Interactions in Non-Equilibrium Hydrogen-Chlorine Reactions.
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
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Effects of non-equilibrium reaction on sound propagation are identified and studied by comparing the observed amplification rates with theoretical predictions. Experiments were conducted in a Pyrex tube filled with a homogeneous mixture of hydrogen, chlorine and argon of different initial compositions and pressures. During the photochemical reaction following ultraviolet irradiation, the amplitude of a two-cycle burst of variable frequency generated at one end of the reaction tube is monitored simultaneously with mixture temperature and chlorine concentration, as the sound burst propagates in the reaction tube and reflects back and forth at its two ends. After correcting for dissipation losses, one obtains the net amplification rate which would conceivably be observed in a nondissipative reacting medium. Significant amplification of the sound fluctuations due to acoustic-kinetic interaction has been consistently observed at different acoustic frequencies and for different mixture compositions and pressures. The amplification rate is typically three times larger than what would be expected from simple consideration of conservation of the acoustic energy, thus demonstrating the significance of the additional contribution due to acoustic-kinetic coupling. Total amplification of up to 80 of the initial sound amplitude was commonly observed over the sound residence time of 0.1 to 0.3 sec..
- Physical Chemistry