Simulation of charging and coupled airflows in corona devices

A hybrid algorithm for simulating electrohydrodynamic (EHD) flows in charge generating devices is described. The computational scheme is a robust time-transient hybrid technique using the boundary integral equation method (BIEM) and the method of characteristics (MOC). This algorithm alternates between solution of the fluid and electrostatic problems. The Navier-Stoke´s equations for the fluid problem, inclusive of EHD effects, are solved using a vorticity-streamfunction BIEM formulation that does not require vorticity boundary conditions to be specified a priori. The non-linearities are handled as volume terms tracked along trajectories as they evolve using the MOC. The electrostatic problem is solved using a combination of the BIEM for charge conservation, and the MOC for current continuity. Sample results, including: space charge, coupled airflows, and electrostatic fields, are presented for the simulation of corotron charging of a xerographic electroreceptor