The Air Force Office of Scientific Research Notre Dame Large Mach-6 Quiet Tunnel (ANDLM6QT)

Key Components MetricDiagram of the ANDLM6QT

Commissioned in 2019, the ANDLM6QT is one of three hypersonic quiet tunnels in the United States and the largest known hypersonic quiet tunnel in the world. It is the only facility capable of studying natural transition for any vehicle geometry. The ANDLM6QT is a Ludwieg-style facility with a high pressure driver tube separated from a vacuum pumped nozzle by a fast acting valve. The ANDLM6QT has multiple features that serve to keep its nozzle wall boundary layer laminar, allowing for quiet test flow. These include a very long nozzle expansion section, a bleed lip at the nozzle throat to eliminate the incoming turbulent boundary layer, and variable heating of the tunnel nozzle. The ANDLM6QT's quiet flow and ability to test at high Reynold's number gives it a unique capability for hypersonic viscous flow testing, whether it be for flow control, shock-wave/boundary-layer interaction, or hypersonic transition studies.

Quiet Tunnel Brochure


Mach Number = 6 Max Reservoir Temperature  = 590 K
Reservoir Pressure = 1-10 bar  Test Time = 1 s (300 ms steady)
Coreflow Length = 3.6 m  Max Reynolds Number/meter = 11 million
Run Modes: Quiet, Noisy Max Reynolds Number= 40 million

Diagnostic Capabilities


Our lab utilizes a wide variety of measurement and diagnostic systems. Kulite and PCB pressure transducers, as well as thermocouples, represent point measurement techniques that are used in our lab. Optical-based methods such as infrared thermography, pressure sensitive paints, and temperature sensitive paints allow for "global" measurements of a quantity at a model's surface. Finally, background oriented schlieren will be implemented in our tunnel to allow for low cost flow visualization. An example of Schlieren imaging is given in the following video, which shows Mach 5 flow over a model alignment probe in the Oxford High Density Tunnel.