The propagation mechanism of cellular detonation

Abstract

The present lecture examined the available experimental and numerical results on cellular detonations. It is concluded that apart from special mixtures where the detonation is only “weakly unstable”, the classical shock ignition and thermal explosion mechanism cannot describe the physical and chemical processes in the highly complex reaction zone of unstable detonations in general. Turbulence will play an important role in both the ignition and the combustion mechanism in the reaction zone of highly unstable detonations. Vorticity and turbulence generation from shock-shock, shock-vortex, shock-density interactions and the baroclinic torque mechanism are considered important in contrast to the velocity gradient shear flow mechanism of turbulence production in incompressible flows. It is recommended that the experimental determination of the hydrodynamic thickness, its correlation with chemical, thermodynamic and transport properties of the mixture and the formulation of a turbulence model to describe the steady mean flow properties of cellular detonation structure are important problems in detonation research for the immediate future.