SBIR-STTR Award

We propose to develop scaling relationships for reaction violence in the cook-off of energetic materials such as explosives or propellants. This will be accomplished by a coordinated effort consisting of data review and analysis. The anticipated results include key non-dimensional parameters that incorporate the thermo-physical, flow, thermodynamic, and kinetic properties of the material, the heating rate in terms of intensity and duration, the thermo-physical properties of the casing and liner (if any), and the strength and degree of confinement of the casing. Furthermore, scaling relationships will be developed for the violence of the reaction relating attributes such overpressure, vivacity, casing fragmentation, and travel distance of fragments to non-dimensional parameters. This scaling relationship will be used to identify practical means of compensating for the reduction of scale in the experiments. Key comparisons and success criteria will be identified to evaluate our scaling approach. The project will also identify data gaps and key tests and instrumentation to be performed in Phase II.

Keywords:
Cook-Off, Cook-Off, Insensitive Munitions, Scaling, Reaction Violence, Hazards., Hazards Classification

Currently, assessment of ordnance items for IM and Hazards Classification (HC) characterization requires full-scale testing which presents a considerable financial, logistical, and environmental burden. Some of these munitions (such as the large rocket motors) cost in excess of a million dollars and their hazard testing is likely to cost several million dollars. Therefore, testing on a smaller scale is preferable, though no reliable sub or small-scale cook-off tests have been identified yet because of the complexity of ordnance response to external stimuli. Using a combination of unique property measurements, tests and simplified engineering models, we propose to develop a methodology to predict the response of full scale munitions to cookoff. For example, we will adapt standard test methods to simulate cookoff conditions and measure the porosity, permeability, density and surface area that describe the thermal degradation state as functions of temperature, pressure and confinement. The expected outcomes of this project are novel test setups and methods, an engineering model for cookoff and a methodology to predict the response of full scale munition systems to heat.

Keywords:
Tests, Tests, Burn Rate, Thermal Degradation, Scaling Analysis, Cookoff, Energetic Materials, Reacti