Measurement of the Thrust-Specific Fuel Consumption of a Small-Scale Jet Engine

Abstract

The performance of a small-scale jet engine is characterized and estimates are provided for the engine parameters relevant during the configuration design phase of a small unmanned aerial vehicle. The engine tested is a P20-SX JetCat engine. Its thrust and thrust specific fuel consumption are measured. Its maximum thrust is determined to be 5.8 lbf. Its measured thrust specific fuel consumption at sea level and zero flight speed is 1.9 h≠1 at maximum throttle and 9.3 h≠1 at low throttle. At maximum throttle, the measured thrust specific fuel consumption of the P20-SX is approximately 40% greater than the estimated value given by traditional methods for estimating engine performance under the same conditions. This experiment provides data that gives a more accurate estimate of the performance of similar- sized engines than these traditional methods, thereby reducing the need for engine testing during the initial design phases of a small aircraft. The design of the test stand used to constrain the engine during testing, and the design of the data acquisition circuit used to measure relevant engine parameters are also presented. A lab manual detailing how the experiment could be run as a pedagogic exercise is given.