Calibration of the AEDC-PWT 16-ft Transonic Tunnel at Test Section Wall Porosities of Two, Four, and Six Percent

Abstract : Tests were conducted in the AEDC Propulsion Wind Tunnel (16T) to determine the centerline Mach number distributions and the tunnel calibration at test section wall porosities of two, four, and six percent. The calibration was conducted over the Mach number range from 0.2 to 1.6. A quantitative evaluation of the effects of Mach number, tunnel pressure ratio, test section wall angle, and test section wall porosity upon the centerline Mach number distributions was determined by analysis of the local Mach number deviations. Limited data were also obtained to provide an indication of the effect of Reynolds number upon the calibration. The results indicate that Mach number distributions of good flow quality are obtained at porosities of two, four, and six percent for test section wall angles which vary from 0 to 0.50 deg. Variation of test section wall porosity, as well as wall angle, significantly affects the Tunnel 16T calibration. Comparison of this calibration with a previous calibration, however, indicates that no new tunnel calibration is required for operation at a porosity of six percent with either a zero or optimum wall angle schedule.