INVESTIGATION OF THE CORE FLOW OF THE HYPULSE HYPERVELOCITY SHOCK TUNNEL

An investigation of the core flow of the HyPulse hypersonic shock tunnel was conducted as part of its recommissioning. In support of the recommissioning effort, a pitot rake was designed, built, and tested to examine several core flow characteristics of the facility and the currently installed nozzle. The primary objectives were to measure the nozzle exit pitot pressure, useful test time, flow uniformity, core flow size, and useful test rhombus size using the pitot rake. Additionally, an attempt to operate HyPulse at the tailored interface condition was made using simple 0D shock tube theory at relatively moderate total pressures and enthalpies. Four conditions were tested, which were theoretically at the tailored condition. Each condition was tested twice, once with the pitot rake 2.54 cm aft of the nozzle exit and once with the pitot rake at 91.44 cm aft of the nozzle exit. From this testing, the resulting shock tube conditions are compared to the predicted conditions from both the 0D theory and the University of Queensland’s L1d results. Each showed considerable error, though this was to be expected as this data will be used to create tuning parameters for HyPulse’s future use. Additionally, each condition’s useful test duration and properties were experimentally determined. Visualization of the core flow at each rake position was achieved with pitot pressure profiles that qualitatively matched historical results. Pressure profiles at the downstream location indicate that there may be a distinct increase in the pitot pressure’s stability, both span-wise and temporally, further downstream of the nozzle exit plane. This indicates that it may be beneficial to place a model somewhat downstream of the nozzle exit plane. The study of two different pitot tip designs resulted in a negligible performance difference being observed, though the design that provided additional protection to the sensors was preferred.