Design and Characterization of an Actively-Controlled Hypersonic Wind Tunnel Nozzle

The Actively Controlled Expansion (ACE) hypersonic wind tunnel at the Texas A&M University National Aerothermochemistry and Hypersonic Flight Laboratory (TAMU NAHL) was recently upgraded with a new nozzle to enable true active control of the Mach number across the operational range of 5 to 8. Servo-driven linear actuators allow continuous variation of Mach number during tunnel operation, while servo-controlled air regulators support fully programmatic operation for repeatable, dynamic Mach- and Reynolds-number trajectories. The new nozzle was installed, and initial shakedown and characterization experiments were conducted. Results from pressure transducers and schlieren imaging demonstrated high-quality, uniform flow throughout the operational envelope, with smooth and stable Mach-number variation during dynamic sweeps.