The temperature of a shock-collapsed cavity

The temperature of the gas enclosed in a cavity collapsing as the result of the passage of a shock wave has importance in considering the safety of reactive materials. This paper assesses the ability of this collapse to ignite an explosive medium in which the cavity is placed. Both jet-impact and hot-gas-ignition mechanisms are considered. A series of experiments have been conducted in which a cylindrical cavity has been collapsed under shock. This geometry has the advantage of allowing details of the gas in the bubble interior to be studied. A further series of experiments is underway to ally this disc-shaped geometry with a spherical cavity using two novel arrangements. The development of these tests has addressed the temperature increase within the cavity. For jet-impact studies, nitromethane is used as the liquid to observe ignition directly. The series of experiments has been coupled with numerical modelling of the multi-material shock interactions to indicate the mechanisms by which ignition and reaction occur.