Calibration and performance characterization of a Mach 5 Ludwieg tube.

ABSTRACT

Calibration, commissioning, and design features of a new Mach 5 Ludwieg Tube wind tunnel at the University of Arizona are discussed. Mach number uniformity and free-stream noise levels are measured using a Pitot rake at a range of unit Reynolds numbers and at multiple spanwise and streamwise positions. The wind tunnel is shown to have a free-stream Mach number of 4.82 with maximum variance less than 0.8% (and less than 0.5% at most streamwise positions). The average free-stream acoustic noise level in the core (based on Pitot pressure) is shown to be less than 1.2% at an intermediate Reynolds number with some regions dropping locally below 1.0%. The core flow region is measured to be 282.4 mm (11.1 in.) in diameter at the nozzle exit.