Event-Driven Simulation of Particle-Particle and Particle-Surface Collisions in Ice Crystal Icing 2019-01-2014

This paper describes event-driven simulations of ice crystal icing test cases in which accretion increases with TWC were consistent with a reduction in particle erosion due to interference between incident and back-scattered (eroded) particle fluxes. The event-driven simulation tracks individual particles, assuming particles travel in straight lines between collision events. The consequences of each collision event (bounce, fragmentation, etc.) are calculated and used to redefine the trajectories of the affected particles for the next collision time update. Particle-particle collisions and particle collisions with bare and iced surfaces are considered. The simulations successfully predict the observed dependence of steady-state accretion size on TWC, at least qualitatively. The tool is also used to investigate the possibility that accretion can initiate by "particle overloading" at very high TWC levels, wherein slow (wet) rebounded particle concentrations become so high that the particles agglomerate.