Sizing of a turboprop unmanned air vehicle and its propulsion system

In this study,a genuine computer code for sizing of an unmanned aerial vehicle (uav) and its turboprop engine by analytical method is developed. payload and fuel weights are primary factors affecting uav size and weight (which need to be fulfilled in terms of flight performance parameters,e.g. lift and drag). the parameters within mission profile such as altitude,speed of aircraft are keys for selecting engine type. engine specific fuel consumption (sfc) defines the total fuel amount to be stored and carried during the flight,which affects the general dimensions and the gross weight of the aircraft. some engine parameters namely,compressor pressure ratio and turbine inlet temperature,have direct influence on sfc. turboprop engine subroutine code developed in this study is within ±1% agreement with commercial engine cycle analysis software gasturb for shaft power,propeller thrust and sfc etc. values,at all mission points of uav. calculated weight,size,endurance values of uav are seen to be close to literature values. literature values indicate some inconsistencies especially for endurance and empty weight of aircraft. considering most dependable references and logical combinations of inputs,error in calculation of uav weight and size is about ±1,5% and for maximum operating altitude is around ±3%. moreover,calculated endurance values are within range of literature values. © 2015 tibtd printed in turkey.