Approximative quantitative aspects of a hot spot

Abstract

To understand the phenomena of initiation and low velocity detonation in liquids an approximate generalized description of bubble motion is suggested. Within this framework it is essential for any detonation to have a two-phase system of high and low compressibility of the components. The dynamic activated high compressibility component (bubble or void, cluster of chemical reaction) always has a phase-locked conservative radiation loss, and in addition, dissipative losses. These force a chemical decomposition in reactive liquids, so that a pressure-coupled chemical reaction is possible. In media of poor reactivity a decoupling may also occur, and, if the radiation loss dominates, even a nonchemical “detonation”, in the sense of a shock wave amplification, becomes possible. The dissipative loss at the boundary of a bubble or void is governed by the medium's viscosity, and is, under some circumstances, the controlling factor. Questions concerning Bowden's hot spots are discussed, and another suggestion, that initiation should occur via dynamic bubble surface instabilities, is explored.