Modeling of Interior Ballistic Gas-Solid Flow Using a Coupled Computational Fluid Dynamics-Discrete Element Method.

Area of Science:

• Fluid Dynamics
• Computational Physics
• Ballistics

Background:

• Conventional interior ballistic models often neglect or simplify particle collision dynamics.
• Particle collisions significantly influence particle movement in nonuniform dilute two-phase flows.
• Understanding these collisions is crucial for accurate interior ballistic simulations.

Purpose of the Study:

• To develop and validate a CFD-DEM approach for simulating interior ballistic two-phase flow.
• To incorporate dynamic particle collision processes into the simulation model.
• To enhance the prediction of complex physics in interior ballistics.

Main Methods:

• Employed Computational Fluid Dynamics (CFD) for the Eulerian gas phase and Discrete Element Method (DEM) for the Lagrangian solid phase.
• Incorporated grain combustion, particle-particle/wall collisions, interphase drag, and heat transfer.
• Utilized AUSM+-up scheme for gas phase, explicit time integration for particle motion, and direct mapping for contact detection.

Main Results:

• The CFD-DEM model accurately captures dynamic particle collision phenomena.
• Verification tests confirm the approach's accuracy and reliability.
• Simulations of an experimental igniter showed good agreement with experimental data.

Conclusions:

• The CFD-DEM approach provides a robust method for simulating interior ballistic two-phase flow.
• This model improves the ability to capture complex physics, including individual particle-scale dynamics.
• The findings have implications for enhancing the design and analysis of interior ballistic systems.