Building and testing a model jet engine

The aim of this study was to design and manufacture a model jet engine. To build the engine, Brayton cycle in theory and aircraft turbojet engines in practice were referred. As the compressor-turbine section of the model, a turbocharger, which was built for a diesel engine, was selected and adopted. During the experiment, turbine inlet temperature was between 630 and 890°C. However, temperature of the turbine outlet and exhaust nozzle temperatures were between 612 and 850°C. At low fuel pressures and at 17607 1/min, turbine inlet temperature was 870°C, combustion chamber inlet temperature was 68°C, manometric pressure was 0,39 bar and the exhaust nozzle temperature was 860°C. The oil pressure was 3,45 bar and the oil temperature was 65°C. When the fuel pressure was around 4 bar, the highest engine speed measured was 48660 1/min. At this speed, the turbine inlet temperature was 636°C, exhaust nozzle temperature was 612°C, compressor outlet temperature and pressure were 65°C and 0,47 bar respectively. Measured thrust values of the model jet engine were between 14 and 20 N.Key Words : Turbocharger, turbojet, a model jet engine