Wind Tunnel for Low Density Flows

The wind tunnel, also known as the vacuum or high-altitude wind tunnel, was built in the 1950s and originally operated at the Hermann Föttinger Institute for Fluid Mechanics at the Technical University of Berlin. Its primary purpose was to model effects in gas kinetic flows with very high Knudsen numbers, as they occur in the initial phase of re-entry. After the facility was handed over to the TU Dresden in October 2001, the wind tunnel was overhauled, repaired and recalibrated in the period from November 2002 to March 2004 as part of student work.

In accordance with its characteristics, the facility is used for tests such as

• Testing the air transport suitability of all kinds of equipment,
• Characterization of the operating behavior of plasma actuators,
• Rapid decompression tests on smaller aircraft structures, especially fasteners,
• Principle investigations for density correction in hot-wire measurements and other sensor systems,
• Investigation of convection problems in gas kinetic environments.

The flow is driven by a 22 kW motor via a radial fan. For very high speeds, cooling of the circuit is provided. The evacuation of the system is done by two vacuum pumps. Accessibility to the measuring chamber is provided by a number of spigots for cable bushings in addition to the two large doors.

• min. working pressure: approx. 500 Pa
• max. speed: 100 m/s
• nozzle diameter: 100 mm
• contraction ratio: 64:1