The Development of Turbojet Based on Turbocharger

This paper explains the process of developing a small turbojet engine based on an available turbocharger. As a study case, turbocharger Turbonetics T70 was chosen as the engine’s compressor and turbine core while the combustion chamber was separately designed and manufactured. An engine performance analysis, with an assumed components efficiencies and pressure losses was done to determine the engine’s thrust at sea level static condition. From the analysis, it was found that the engine produces maximum thrust of 208 N at 105,800 rpm. The compressor pressure ratio (CPR), turbine inlet temperature (TIT) and air mass flow at its maximum thrust are 4.23; 1,260.4 K and 0.4931 kg/s respectively. After all parts were completely built, the engine was assembled and several functional tests were conducted. The objective of the test was not to measure the thrust but to find out whether the engine can perform a self sustains operation or not. The tests results show that the idle speed is around 52,000 rpm with the idle exhaust gas temperature (EGT) is about 1,053 K. The maximum speed achieved during functional test is 80,000 rpm. In the future, performance tests will be conducted to investigate the engine’s thrust, specific fuel consumption and efficiencies.