Design and Characterization of the Notre Dame STEM Mach 6 Ludwieg Tube

The University of Notre Dame has designed and constructed a new Mach 6 Ludwieg tube for the purpose of hypersonics research and education. The tunnel uses a fast acting plunger valve to actuate the flow, providing run times of 55 ms. The Mach 6 flow is generated through a 0.28 meter diameter nozzle. Pitot pressures are measured on the centerline, and with a rake. The nominal Mach number was found to be 5.8 and pitot pressure fluctuations were 1.5 %, both varying with unit Reynolds number. Possible air liquefaction is present at high Reynolds numbers, which is apparent from a rise in noise.