Effects of each operating condition on the maximum pressure in an imploding detonation apparatus with a pre-combustion chamber

Abstract

Imploding detonations can generate ultra-high pressures at their implosion centers. In this basic study, we measured the maximum pressure in an imploding detonation apparatus with a pre-combustion chamber. The aim was to investigate such ultra-high pressure states for industrial use; namely, as a microorganism treatment technique driven by underwater shock waves. The experimental apparatus is fitted with an exchangeable nozzle for altering the minimum converging radial distance. The variable experimental conditions are the inner diameter of the nozzle, the initial pressure, the equivalence ratio, and the concentration of the nitrogen diluent. We found that the maximum pressure increased with increasing inner diameter of the nozzle, because the duration time of the flame passing the nozzle increased. The maximum pressure was also an increasing function of the initial pressure and the equivalence ratio. High pressure was maintained up to nitrogen concentrations of approximately 65%. This result was attributed to detonation of the overdriven state and reduced propagation speed of the flame.

Keywords

• imploding detonation
• shock high pressure
• minimum converging radial distance
• equivalence ratio
• diluent