STUDIES OF SUPERSONIC VEHICLE ELECTRIFICATION

Theoretical and experimental studies of airborne vehicle electrification processes are described. Laboratory experiments with projectiles fired through an ice-fog cloud were used to study the variation of frictional charging with air speed at supersonic speeds. These experiments demonstrated that the charge imparted by each particle decreases with increasing speed at supersonic speeds, apparently because of ice crystal melting on impact.

Flight instrumentation has been designed and fabricated to measure electrification parameters and effects on a supersonic test aircraft. The instrumentation measures, charging rate, discharging rate, charge per particle, aircraft potential, streamer current and number of streamer pulses, variation of effective frontal area, and noise spectrum. The philosophy of the design and construction of the flight test experiments and equipment are discussed. The flight test instrumentation has been installed on an F-4 aircraft, and test flights are being conducted.