Integrated rheology model: Explosive Composition B-3

ABSTRACT

Composition B-3 (Comp B-3) is a high explosive formulation composed of 60/40wt% RDX (1,3,5-trinitroperhydro-1,3,5-triazine) /TNT (2,4,6 trinitrotoluene). Above approximately 78°C this formulation partially melts to form a multiphase system with solid RDX particles in a molten TNT matrix. This multiphase system presents a number of phenomena that influence its apparent viscosity. In an earlier study explosive Composition B-3 (Comp B-3, 60/40wt% RDX/TNT) was examined for evidence of yield stress using a non-isothermal falling ball viscometer and a yield stress model was proposed. An integrated viscosity model suitable for use in computational fluid dynamics (CFD) simulations is developed to capture the transition from a heterogeneous solid to a Bingham viscoplastic fluid. This viscosity model is used to simulate the motion of imbedded spheres falling through molten Comp B-3. Comparison of the simulations to physical tests show agreement between the positions predicted by the model and the measured locations of the spheres as a function of temperature between 90C and 165C.

KEYWORDS:

• Bingham plastic
• molten
• multiphase flow
• viscosity
• yield stress

Acknowledgments

The authors acknowledge Natalya Suvorova, Dennis Remelius, Laura Smilowitz, and Brian Henson of the Los Alamos National Laboratory Chemistry Division for contributing experimental data. Los Alamos National Laboratory is operated by LANS, LLC for the United States Department of Energy: [Grant Number DE-AC52-06NA25396].