Effects of atmospheric-pressure discharge type on ionic wind velocity for needle-to-cylinder electrode

A needle-to-cylinder electrode configuration was proposed to generate an ionic wind at atmospheric pressure. Experiments were conducted with negative voltage ranging from 0 to -20 000 V at atmospheric pressure and room temperature. Negative corona, glow, and arc discharges in ambient air were achieved without external airflow, as confirmed by some typical characteristics of their discharge waveforms and images. The experiments indicate that: (1) the discharge current in a glow discharge is larger than that in a corona discharge; (2) the ionic wind velocity does not increase monotonically with increasing discharge current; and (3) the ionic wind velocity increases with increasing voltage in the corona discharge phase, while decreasing in the glow discharge phase. A detailed study was conducted on why varying behaviors occur for these different types of air discharges and how they affect electrohydrodynamic flow. The results help in establishing a guide for electrohydrodynamic design. (C) 2016 American Vacuum Society.