Unrestricted.2016-11-142011-02-192016-11-141984-12http://hdl.handle.net/2346/21835The effects of boundary layer development and turbulence on a gas-blown spark gap switch operated in the self breakdown mode are presented. The switch consisted of two electrodes mounted flush in the diverging walls of a wind tunnel. The electrode spacing was 2.54 mm at the minimum separation distance and the wind tunnel had an aspect ratio based on the minimum separation distance of 40:1 to insure two-dimensional flow. To obtain various stages of boundary layer development for laminar flow, entry lengths of 0, 6.19, 17.46, 22.78, and 57.3 cm were used. These were tested at divergence angles of 5.0 and 10.0 degrees. Turbulence was investigated by placing a coarse, plastic grid 7.62 mm" upstream of the minimum electrode spacing using the 22.78 cm entry length and a 10.0 degree divergence angle. The gas used was instrument grade dry air (< 10 ppm H2O), and the electrode material was 304 stainless steel. It was found that switch performance at low flow velocities was improved with entry lengths up to 17.46 cm and then deteriorated with increasing length. This suggests that there is a stage of boundary layer development that produces optimum switch operation at minimum flowrates. The results also suggest that there is an average gas density level that must be attained at the minimum separation point before the maximum voltage can again be applied to the switch. For the only turbulence test conducted, 10.0 degree divergence angle with an entry length of 27.78 cm, switch performance was improved as compared with the laminar case.application/pdfengLaminar flowBoundary layerTurbulenceBreakdown voltageElectric discharges through gasesThesis