Complex Particle Kinetics: Particle Interactions Over the Full Range of Collisionality

Summary form only given. In previous work developing the Complex Particle Kinetics (CPK) method we utilized fragmentation, merging, and self-consistent particle evolution (Hewett, 2003) along with a binary collision algorithm (Larson, 2003) in our pursuit of a method that would simulate the transition from continuum to fully kinetic physics. CPK is built upon simulation particles that carry a Gaussian spatial profile and an internal Maxwellian velocity distribution. We recently incorporated ideas from the Finite Mass Method (Gauger et al., 2000) and have completely changed how the particles interact. The self-consistent particle evolution has also been generalized. The simulation particles move under the influence of internal and external forces and can expand, contract, and rotate as well as overlap and pass through one another. The resulting algorithm captures the continuum limit without prohibitive expense and smoothly transitions to the kinetic limit. Particle fragmentation and merging are still viable options within the algorithm and will be exploited to increase resolution where required and decrease expense where feasible. We will present an overview of the algorithm and the results of some recent simulations.