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Low Density

University of Oxford

The Low Density Tunnel (LDT) is rarefied flow facility, with the ability to produce flows with high Knudsen numbers representative of those experienced in the slip regime. The facility is continuous and is capable of measuring aerodynamic coefficients by use of a magnetic suspension balance. The tunnel has a 0.18 m diameter. Flow visualisation is via high speed Schlieren imaging, hot films, and thermographic liquid crystal.

Test Section 1 size:
0.18m (diameter)
Rarefied Flow
Mach Number: 5.5 – 9
Working gas: Air (Knudsen No: 0.001-0.3)

Maximum Flow Speed: Mach 5.5 – 9
Reynolds No: 60x10³/m – 120x10³/m

Run Time: Continuous

Testing Capabilities:
Model Support: Magnetic suspension and balance system.

Data Acquisition: Multiple channel high speed data acquisition system.
Outputs: Forces and Moments, pressure, temperature.
Flow visualisation: High speed Schlieren, hot films, thermographic liquid crystal.
Specialist Rigs:
Large diffusion pump drive system.
Three-dimensional traverse for docking and stage separation simulation.
Wireless Data Acquisition
Force balance and instrumentation