Transonic Wind Tunnel

Introduction

The Transonic Wind Tunnel (TWT) is ARA’s primary test facility. It is used to test aircraft models at speeds from Mach 0.2 to 1.4. A wide range of models and test types can be accommodated. Follow the link below for an explanation of what "Transonic" means:

• What does "Transonic" mean?

How the Transonic Wind Tunnel Works

The TWT circuit is 63m (207ft) long by 12.5m (41ft) wide. Viewed from the top, the air moves anticlockwise around the circuit. Starting at the Fan Section, high pressure generated by the fan drives the air through the Low Speed Diffuser and into the Cooler. The air flows around two sets of Corner Vanes into the Settling Chamber and through the Flow Smoothing Honeycomb. The air is accelerated through the Contraction and Nozzle into the Test Section where the model is being tested. The air flows past the model at high speed then exits into the High Speed Diffuser. The air is turned around another two sets of Corner Vanes before returning to the Fan Section.

For further information on the tunnel circuit, follow the links below:

• Fan Section and Low Speed Diffuser
• Cooler
• Corner Turning Vanes
• Settling Chamber and Flow Smoothing Honeycomb
• Contraction and Flexible Nozzle
• Test Section and Pressure Shell
• Moveable Section and High Speed Diffuser

Technical Information

The TWT has a large test section 2.74m (9ft) wide by 2.44m (8ft) high and can accommodate full models up to 1.83m (6ft) long or half models up to 3.5m (11.5ft) long. Perforated walls with 22% open area ratio enable tests to be made on models throughout the transonic speed range with only small interference effects except near Mach 1.0. A Mach number range from 0.2 to 1.0 is extended up to 1.4 by a combination of flexible throat and suction through the perforated walls.

A typical unit Reynolds number at Mach 0.8 and atmospheric pressure is 13 million per meter (4 million per foot).  The stagnation pressure can be varied between 0.8 and 1.2 atmospheric pressure.

The incidence range for models is -10˚ to +40˚ and the roll range is ±180˚.

Over 200 channels and several hundred pressures can be recorded simultaneously at a rate of up to 10 data points per second. High speed data recording is also available.

For further technical information, please download the documents at the bottom of the page and follow the link below to Test Technologies and Services which can also be accessed via the navigation panel on your left.

• Test Technologies and Services