Hydrodynamical simulation of the electric wind in a cylindrical vessel with positive point-to-plane device

Electrical corona discharges at atmospheric pressure in a positive point-to -plane configuration create an electric wind from the point to the plane wh ich, in a closed cylindrical vessel, generates in a few seconds axisymmetri cal vortices in the vessel. Photography and video recording show that a sma ll ring vortex appears around the discharge axis, close to the plane, enlar ges and progressively fills the vessel up to a stationary situation. A simplified stationary model was first used in order to take into account the measured values of the wind velocity along the discharge axis as well a s the velocity held lines visualized by smoke particles. Simulation and exp erimental results are in fairly good agreement, and a few particular adjust ments concerning temperature profiles were made to improve the numerical re sults. Then, a dynamical model, including the effect of the repetitive ionizing fr onts (streamers) occurring in the filamentary discharge, allows one to rend er an account of the transient evolution of the velocity field lines toward s the stationary vortices. Although the numerical simulation could not be c ontinued to a steady state, it shows that a small ring vortex is created ne ar the point electrode, moves rapidly from the point to the plane and then begins to enlarge at the right (experimental) place.