DESCRIPTION AND INITIAL OPERATING PERFORMANCE OF THE LANGLEY 6-INCH EXPANSION TUBE USING HEATED HELIUM DRIVER GAS

摘要

A general description of the Langley 6-inch expansion tube is presented along with discussion of the basic components, internal resistance heater, arc-discharge assemblies, instrumentation, and operating procedure. Preliminary results using unheated and resistance-heated helium as the driver gas are presented. Driver-gas pressure ranged from approximately 17 to 59 MPa and temperature ranged from 300 to 510 K. Test-gas—acceleration-gas interface velocities of approximately 3.8 to 6.7 km/sec were generated using air as the test gas and helium as the acceleration gas. Test flow quality and comparison of measured and predicted expansion-tube flow quantities are discussed.