SBIR-STTR Award

The objective of this project is to develop a methodology for predicting reaction violence of full-scale munitions in either a fast or slow cook-off scenario. This methodology will use a combination of existing heat transfer models and thermal stimulus simulation tools coupled with an empirical model to be developed from data collected from various lab and subscale experimental hardware. Hardware may include but will not be limited to the NAWC Controlled Heat Flux Device, the US DOT Koenen test and the NAWC small scale cook-off bomb. The methodology will be based on a hierarchical approach to validation/uncertainty quantification (V/UQ) to achieve quantified error bounds on the predicted response quantity of interest, the kinetic energy or container fragments and/or the overpressure. The hierarchical approach will also help identify where deficiencies exist that might have a first order impact on the response quantity of interest. Steps can then be taken in Phase II of the project to eliminate these deficiencies through a combination of modeling and experimental quantification. The testing matrix required for the development of the empirical model (including experimental conditions, parametric studies, instrumentation, etc.) will be outlined in this phase of the project and a few scoping tests will be run. However, the majority of the required testing will be conducted in Phase II.

Keywords:
Decision Tree, Decision Tree, Fragmentation, Cook-Off, Hierarchy, Munition, Reaction Violence, 1-D Heat Transfer, Uncertainty Quantification

Perform research and development to produce modeling, simulation, and testing capabilities sufficient to predict the reaction violence for hydrazine (H-70) and Monomethyl Hydrazine (MMH) and minimize the uncertainty thereof. This will be accomplished through empirical modeling using and expanding the capabilities of the Integrated Violence Model (IVM). The IVM will be adjusted dependent upon outcomes from laboratory experiments. To further expand the IVM, small scale experiments such as internal ignition, instrumented Koenen and thermal cook-off will be performed. In-addition large scale explosive range testing will be conducted. Model performance verification will be based on replication of the experimental behavior. If the model differs, it will be iteratively modified to match the specific behavior of liquid hydrazine. Once the model can replicate laboratory testing results, a scaled-up scenario of the application will be predicted by the model and then validated with small-scale and large-scale test results. Key outcomes of the model include the internal pressure and temperature as a function of time. Parameters that define the outcome are the burn rate and pressure exponent of the hydrazine as well as its phase behavior during burning. Through the implementation of a defined heuristic approach the model will be optimized to ensure that the chemical, physical, and explosive characterization of hydrazines in the specific application scenario is accurate. All major and minor technical factors, utilizing first principle chemistry and physics analysis, will be applied to the IVM to predict and prevent any fast cook-off, slow cook-off, permutation thereof event and adverse conditions initiating event within identified facilities at HAFB that contain either H-70 or MMH. Risk assessment packages will be developed including a Process Hazards Analysis and an off-site consequence analysis. These investigation efforts will commence at unloading of material from the delivery truck at HAFB facilities and will continue through the complete array of processes including spills, neutralization, and eventually final disposal. The risk assessment will be used to develop standalone design specifications that are tailored to hydrazine processes, safety, and spill containment by incorporating the findings from the aforementioned research and development investigations and assessments. This shall utilize the existing facility improvement specifications as a baseline and will be expanded through coordination and collaboration with the originator of the existing facility upgrade design package. New training packages for H-70 and MMH will be provided to HAFB hydrazine operations personnel and will be based on findings of this SBIR effort. This training will be presented to operators, engineers, maintenance, and management personnel.These training packages will be an implementation of all things learned in this SBIR effort.