This work was done by David W. Hughes of Goddard Space Flight Center. For more information, download the Technical Support Package (free white paper) at www.techbriefs.com/tsp under the Information Sciences category. GSC-15364-1
Algorithm for Computing Particle/Surface Interactions
An algorithm has been devised for predicting the behaviors of sparsely spatially distributed particles impinging on a solid surface in a rarefied atmosphere. Under the stated conditions, prior particle-transport models in which (1) dense distributions of particles are treated as continuum fluids; or (2) sparse distributions of particles are considered to be suspended in and to diffuse through fluid streams are not valid. In the present algorithm, individual particle/surface interactions are modeled. The algorithm uses a few key parameters that can be determined experimentally for the particles of interest in a given application: These parameters are the coefficient of restitution, coefficient of transfer of momentum, diffusivity, and sticking velocity. If many representative particles are tracked through modeling by use of this algorithm, a statistically likely distribution of particles can be obtained.