Accurate Insensitive Munitions Modeling Tool Coupling Detailed Chemical Kinetics and Physical Models

Understanding the response of solid rocket motors under cook-off conditions is important to the safety of the military’s weapon arsenal. In this SBIR, CFDRC, teamed with Merrill Beckstead of Brigham Young University (BYU) and ATK Launch Systems, proposes to develop a software toolkit for simulating the response of solid rocket motors (SRM) to fast cook-off events. The complete software package will include multiple codes with different fidelity levels and dimensionality (1D, 2D, and 3D). Include in the software package will be the 1D BYU cook-off code with detailed and reduced kinetics for AP/HTPB, CFDRC’s 3D structural mechanics code named COBI, and ATK’s thermal code incorporating composite case materials. The software’s modularity will enable other codes to be attached as desired, such as ALE3D. In Phase I, feasibility of the software was demonstrated by comparing predictions of the software with initial thermal cook-off data from China Lake. Good agreement was seen. In Phase II, the software will be further enhanced for efficiency (i.e. reduced run times) and accuracy. The improved software package will be extensively validated and calibrated against sub-scale China Lake data and NOSSA data. Scalability will then be demonstrated by validating against full-scale MDA SRM data. To ensure technology transfer of the software to OEMs, CFDRC has acquired the services of ATK to be a beta tester of the software, followed by ATK performing cook-off simulations on real SRM applications.