The history of UT Arlington's transonic wind tunnel began with a visit by two professors to the AEDC and Marshall Space Flight Center to view their transonic Ludwieg tube facilities in 1976. The professors were looking for a plan to build a smaller version of the AEDC wind tunnel at the university, but when it was toured they found out that it had just been decommissioned. The Ludwieg tube was developed by the Air Force as a prototype for the National Transonic Facility Development Program, but another cryogenic tunnel concept was selected and the NTF facility was constructed at the NASA Langley Research Center. The professors jokingly told the AEDC project manager to consider donating the entire prototype Ludwieg tube to UT Arlington, which was later taken as a serious offer. Not long after the visit, it was declared government surplus and donated in 1978, showing up at the rail head in Arlington on three specialized flat bed cars.
Transonic tunnel and equipment arrives in Arlington.
Moving the main tube of the transonic tunnel.
The tunnel assembled in the old ARC building.
The tunnel assembled in the old ARC building.
Several years were required to develop the supporting systems and software for the tunnel, and the first test was conducted in January of 1984. The tunnel has a Mach number range of 0.5 to 1.2 and a Reynolds number range of 40 to 400 million per meter. The tunnel is capable of independently varying the Mach and Reynolds numbers over its full operating range. The test section has a porous wall design with a rectangular cross section measuring 18.5 by 23.2 cm. The test section length is 64 cm. The porous wall design minimizes shock wave reflections, alleviates tunnel wall interference effects, and allows acceleration to low supersonic Mach numbers with a fixed area ratio convergent nozzle.
The main tube of the transonic tunnel is delivered to the new ARC building.
The tunnel operates on an expansion wave principle. The charge tube has a 36 cm diameter and a length of 34 m, and can be pressurized up to 700 psi. The tunnel is started by opening a pneumatic sliding-sleeve valve located downstream of the diffuser. The resulting expansion wave travels upstream to the charge tube and starts the flow through the nozzle and test section. The steady flow lasts for about 120 milliseconds. The flow quality is excellent with a 0.5 percent variation of the test section Mach number and a background turbulence level of about 1.0 percent.
Video of a transonic test.
Below are some of the original publications and manuals for the tunnel:
Schematic of the transonic Ludwieg tube wind tunnel
Views of 1) the test section with the bottom plate removed to show the plenum area, 2) the sliding-sleeve valve, and 3) the outside of the test section with the plenum cutter.
