Experimental investigation for the different blend ratios of kerosene with diesel on the exergetic performance of a small-scale turbojet engine for UAV missions

Abstract

The main purpose of this study is to experimentally analyze the exergetic performance of a small-scale turbojet engine that can be used in unmanned aerial vehicles (UAVs) when different blend ratios of kerosene with diesel are necessary, like in extraordinary situations. Comparative analysis was performed to understand the effects of the use of various diesel rates on the jet engine’s performance. To maintain air operations when refueling is required, easy-reachable fuels can help for short but important periods. In cases when there is a need for the use of a quick-reachable fuel in war conditions, diesel may be a suitable fuel. The UAV turbojet engine consists of a radial compressor, an annular combustion chamber, an axial turbine, and a propelling nozzle. The compressor, combustion chamber, turbine, and nozzle were evaluated by using the exergy analysis method. The performance parameters to evaluate the turbojet engine components were specific fuel consumption, thrust, overall exergy efficiency, and air-to-fuel ratio. The turbojet engine was operated at different throttle settings to monitor the changes in the performance parameters. As a result of using different kerosene and diesel fuel blends at different throttle settings, it was observed that the findings were consistent. Generally, the maximum exergy efficiencies took place in the turbine except for the full throttle settings. The minimum exergy efficiencies belonged to the nozzle. It was observed that irrespective of which fuel blend was used, thrust specific fuel consumption values decreased as the throttle setting increased. On the other hand, thrust values, overall exergy efficiencies, and air-to-fuel ratios had an increasing trend as the throttle setting was increased.