Development of High Unit-Reynolds Number Supersonic Wind Tunnel Facility at the University of Texas at Arlington

A high unit-Reynolds number supersonic wind tunnel facility has been completely designed and developed in-house to study external and internal flows at representative high-speed flight conditions in the air-breathing corridor. The tunnel operates between Mach 1.5 and 3.0 in cold-flow conditions, with run times up to 30 seconds and unit Reynolds numbers of 50 to 200 million per meter. This allows flight components to be scaled down by a factor of ≤40 for ground testing. The facility incorporates a contoured supersonic nozzle with a 3 in X 3 in square exit and a 15 in long test section. The tunnel can replicate the flow conditions of high-speed flight components with perpendicular characteristic lengths up to ~8 ft for external flows and parallel characteristic lengths up to ~16 ft for internal flows. Key development efforts included the high-pressure gas-supply system, plenum, nozzle, optical-access test section, diffuser, exhaust silencer sizing, tunnel instrumentation, control system, safety systems, and remote operation systems. Successful shakedown tests using the Mach 2.0 nozzle demonstrated stable diffuser operation and clean flow in the test section at static pressures as low as 230 mbar when exhausted to ambient (~1 bar). High-Reynolds number operation at static pressures above ≥1 bar in the test section was also carried out successfully.