Ionic Wind

Ionic wind is a term that is used to describe an electrohydrodynamic flow that occurs due to a corona discharge.

When ions are created at a high-voltage corona electrode, coulombic forces that are exerted on the ions create an ionic wind. The corona electrode can be either positive, as in the example below, or negative. The ions accelerate towards the oppositely charged collector electrode due to Coulomb forces. Ions collide with the electrically neutral gas and increase the overall velocity in the direction of flow. Typically, the collector neutralizes the ions so that the electric current density beyond the collector electrode is close to zero.



The ionization of the fluid surrounding a charged conductor (corona electrode) with high curvature causes an electrical discharge, called the corona discharge. The corona phenomenon occurs when the potential of the electrode is high enough to create a thin plasma sheet around the electrode, but not high enough to form an arc between them.

You can model ionic wind simulations in Simcenter STAR-CCM+ and modify the set-up to maximize convective flow while minimizing power consumption. For example, you can vary aspects such as voltage or distance between electrodes, and determine the effect on the velocity of the particle flow at the outlet. For many applications, the aim is to minimize the loss of ions beyond the collector electrode. However, you can also adjust the set-up to maximize the electric current density beyond the collector electrode — for example, to produce a focused flow of ions for cleaning applications.

In Simcenter STAR-CCM+, you can create a surface integral report to test if the electric charge that is transported through the domain is conserved. The Boundary Specific Electric Current field function can be used for the surface integral report along with the boundaries of all regions which make up the simulated ionic wind domain set as parts. In a perfectly converged, steady state simulation the total surface integral over all boundaries is expected to be small compared to the largest integral value of a single boundary.

To model ionic wind, follow the steps to model ionic flux using the Electrostatic Potential model. See Modeling Ionic Species Flux.