Initiation, Combustion and Transition to Detonation in Homogeneous and Heterogeneous Reactive Mixtures: A Summary
Final rept. 1 Jun 80-31 May 81
ILLINOIS UNIV AT URBANA DEPT OF AERONAUTICAL AND ASTRONAUTICAL ENGINEERING
Pagination or Media Count:
Certain aspects of ignition source effects in reactive fuel-air mixtures are discussed. These aspects include effects of chemical sensitizers, flame acceleration, flame area, and ignition point location. The other area involves the hydrodynamic modeling of ignition and flamespreading in granular energetic solids to predict the potential for deflagration-to-detonation transition DDT. Key results in the first area are that chemically sensitized clouds can lead to detonation, that flame acceleration or a large increase in the time rate of increase of the flame area are needed for transition from deflagration to detonation and that it is very difficult to generate damaging overpressure from edge-ignited combustion even for very high subsonic burning velocities. The research dealing with analysis of DDT in porous high energy solid propellant has shown for the first time actual steady-state detonation solutions, following the unsteady flow, for materials with sufficient porosity and critical burning rate properties. Limits of the run-up length to detonation are predicted as a function of propellant chemical energy, burning rate, bed porosity, and granulation size. The detonation states conform to realistic measured conditions for porous HMX and RDX propellants.
- Combustion and Ignition