Micro-turbine engines have been developed for specific flight applications. They have been

used in unmanned aerial vehicles (UAVs), which were designed for short flight duration. A lot of

different kinds of UAVs are now operating worldwide. Another common application for small gas

turbines is an auxiliary power unit (APU) supplementing aircraft engines which provide additional

power when required(1,2). Because of the small size micro-turbine engines show small mass flow

rates of air, low pressure ratios, but very high rotational speeds. A micro-turbine engine chosen for the study is KJ 66 (Fig.1), which is one of the most robust small engines with available design.