Shock wave amplification and shock-to-detonation transition in a two-phase mixture of liquid triethylaluminum with superheated steam

Abstract

The paper presents the experimental proof of shock wave amplification and shock-to-detonation transition (SDT) in a two-phase mixture of liquid triethylaluminum (TEA, \(\hbox {Al}(\hbox {C}_{2}\hbox {H}_{5})_{3})\)—a pyrophoric material reacting with water—and superheated steam in a shock tube. Fine synchronization of TEA injection in the flow of superheated steam with the arrival of a decaying shock wave is shown to change the shock wave dynamics from attenuation to amplification followed by propagation with a nearly constant velocity of 1500–1700 m/s (at a small dose of TEA injection) and 2000–2300 m/s (at a large dose of TEA injection) in a tube during a certain time interval. These speed levels are consistent with the thermodynamic calculations for the detonation speed in the fuel-lean and near-stoichiometric TEA–superheated steam mixtures, respectively. With the small dose of TEA injection, the pressure profiles recorded in the experiments do not generally correspond to the pressure profiles relevant to detonation waves, whereas with the large dose of TEA injection, the pressure profiles resemble those for detonation waves.