Micro/nano flows: vorticity generation

Abstract

Vortical structures have been observed to develop in electrically driven fluid motion at the micro/nano scale, but no coherent theory has been put foreword in the literature to explain such a development. The present paper gives several results in a theory based upon the classical field equations. In particular, it is shown that the origin of vorticity production resides in the applied electric field interacting with any ion concentration gradients present in the fluid as defined by the vorticity equation. This is in addition to any viscous layer vorticity diffusion that may also exist in the flow.