Commissioning of a Supersonic Nozzle Control Regulator in the TUSQ Facility

Ground testing facilities are critical for the development of flight vehicles, particularly at supersonic and hypersonic speeds. Thework presented herein describes the initial commissioning of a Supersonic Nozzle Control Regulator ‘SpNCR’, projected to produce Mach 3 flows at unit Reynolds numbers up to 80 × 10^6 m^(−1) using the hypersonic wind tunnel infrastructure at the University of Southern Queensland known as ‘TUSQ’. The SpNCR utilises a reservoir, spool valve and regulator to achieve the necessary stagnation condition upstream of the nozzle throat and has so far produced Reynolds numbers up to 40 × 10^6 m^(−1) for a Mach 3 nozzle with a nozzle exit diameter of approximately 220 mm. The spool valve completes its full stroke within 100 ms, demonstrating good performance in comparison to similar facilities. It was necessary to limit the available reservoir volume in the present commissioning activities, but it was still possible to achieve a 50 ms period of quasi-steady flow with a nozzle exit Mach number of approximately 3.2. Regulator characterisation identified discharge coefficients close to unity for the case where the regulator had 50% open flow area, and about 0.6 for the fully open case. Comparison of measured pressure histories to simulated results from a thermodynamic model for SpNCR operation demonstrate sufficient agreement to conclude the model is a reliable guide for future tuning of conditions.