Ignition of a vapor-gas bubble in a liquid

Abstract

Existing theories of hearth thermal ignition do not consider hydrodynamic expansion of the heating hearth, and are therefore limited in evaluating the possibility of ignition of a heated bubble in a liquid. This paper offers the results of a theroretical investigation of thermal explosion of a spherical bubble located within an infinite liquid and filled with a reactive mixture of gas and vapor. The equations describing the bubble boundary motion in the liquid, and the state of the gas within the bubble are derived. The following characteristics are distinguished: the adiabatic thermal explosion induction period, the expansion time, and the bubble thermal relaxation time. Numerical calculation is used to find the critical conditions for thermal explosion of an expanding gas bubble in a liquid explosive. The effect of gas parameters and liquid viscosity on gas ignition in the bubble is also considered.