ABSTRACT
All convective transport involves fluid motion and nearly every transport situation of practical importance involves convection. The balance equation considers convection in an out of the control volume, diffusion through the surfaces of the volume, generation of a species via reaction, and accumulation within the control volume. The balance equation on charged species a considers both forms of convection plus diffusion, generation due to a reaction or charge recombination, and accumulation of charged species. One of the classic examples of a solution to the momentum equations is creeping flow about a sphere. The continuity equation is an overall mass balance about a control volume.
