Gas dynamic effects on diffuse electrical discharges in air

Effects of velocity from flows with and without grid-generated turbulence on the power input to a diffuse discharge are presented. Density dependences and some observations from flow orientation with respect to the electrodes are also reported. Improvement of the diffuse discharge power is noted as a result of turbulent flows at subatmospheric density conditions - as much as 500 times the maximum no-flow power. Density changes were obtained with a diffuser; the discharge geometry ordinary-mode consists of an upstream pin-rack electrode and a downstream wire-mesh electrode, typically 2.9 cm apart. A model for the interaction of the ionization/recombination region at the anode pin tips is presented. The voltage just prior to the glow collapse decreases somewhat in the ordinary (or anode-to-cathode) flow mode and increases in the reverse and cross-flow modes. The current just prior to the glow collapse increases markedly under the action of a turbulent flow.