ABSTRACT
Built in the early 1950s at NASA Ames Research Center in Mountain View, California, the Unitary Plan Wind Tunnel (UPWT) is now a National Historic Landmark. It was a research facility used extensively to design and test new generations of aircraft, both commercial and military, as well as NASA space vehicles, including the space shuttle. The UPWT is a set of three wind tunnels that comprise three test sections: an 11 × 11 ft transonic tunnel (Mach 0.40 to 1.40); a 9 × 7 ft supersonic tunnel (Mach 1.55 to 2.50); and an 8 × 7 ft supersonic tunnel (Mach 2.45 to 3.45), all capable of operating at variable stagnation pressures. The major common element of the tunnel complex is its drive system, which consists of four interconnected electric motors that can provide 134.23 MW (180,000 hp) continuously. The transonic wind tunnel is a closed-return, variable-density tunnel with a fixed geometry, a ventilated throat, and a single-jack flexible nozzle. Airflow is produced by a three-stage, axial-flow compressor. The original compressor contained aluminum blades.
