Small Turbojet Altitude Test Facility with Two Stage Turbocharger Inlet Air Cooling

摘要

Detailed air vehicle design requires accurate values for propulsion system performance throughout the entire flight envelope. The small "hobbyist" turbojet market segment shows promising performance at sea-level static conditions but test data is missing for more useful portions of the flight envelope of many commercial and military applications. An altitude test facility was developed to simulate flight conditions and test engine performance. Existing air facilities at Air Force Research Laboratories (AFRL) on Wright-Patterson Air Force Base (WPAFB) were available to generate vacuum for altitude simulation. An air-cooler was developed using automotive turbochargers to reduce turbojet inlet air down to temperatures found at altitude. The facility developed is capable of simulating altitudes in excess of 10,000 m. The design and operation of the turbo-coolers and results of initial checkout tests are presented. Calibration tests confirming thrust measurements for a dummy turbojet are also presented.