Unmanned Aircraft Systems (UAS) are propelled through reciprocating piston engines, turbine engines, and electric motors that use batteries, solar, and fuel cells. Since these different propulsion technologies are challenging when comparing systems, establishing equal safety levels, and dictating performance requirements, the propulsion system is thus disintegrated into various subsystems (Amici et al., 2021). These subsystems include an energy source, an energy transformer, a power plant, propulsion, and a control effecter. This essay describes three unmanned aircraft systems and decomposition methodologies on those UAS, summarizing insights obtained through the decomposition and analysis.
Boeing Insitu RQ-21 Blackjack (RQ-21A) is a UAS manufactured by Boeing Insitu, USA, to survey and conduct multi-mission intelligence and reconnaissance missions over the land and sea. It is designed to perform time-sensitive targets with the required precision, destroying those targets (Writer, 2018). Its gross takeoff weight is 134 lb., wingspan or width is 16.1 ft., and length is 7.2 ft. The RQ-21A UAS uses a gas turbine and uses petroleum extracts as its energy source. The energy is transformed by burning the petroleum extracts resulting in heat production and massive pressure on the operating environment. RQ-21A uses an 8 HP reciprocating engine with EFI as its power plant. A propeller is used as its propulsion effecter, and the fuel flow and propeller pitch constitute its control effecter (Writer, 2018). The UAS system performs with a range equal to 1,491 miles, an endurance of 16 hours, a maximum airspeed of 80 KTS, and a ceiling altitude of up to 15,000 ft.
General Atomics MQ-9 Reaper (MQ-9 Reaper) is a UAS manufactured by General Atomics Aeronautical Systems, Inc. to survey and conduct multi-mission intelligence and reconnaissance missions over the land and sea. It is designed to perform time-sensitive targets with the required precision, destroying those targets (Air Force, 2022). Its gross takeoff weight is 10,500 lb., wingspan or width is 66 ft., and length is 36 ft. The Reaper UAS uses a gas turbine and uses petroleum extracts as its energy source. The energy is transformed by burning the petroleum extracts resulting in heat production and massive pressure on the operating environment. MQ-9 Reaper uses a Honeywell TPE331-10GD turboprop engine as its power plant. A propeller is used as its propulsion effecter, and the fuel flow and propeller pitch constitute its control effecter (Air Force, 2022). The UAS system performs with a range equal to 1,150 miles, a toleration time of 27 hours, a top airspeed of 240 KTAS, and a ceiling altitude of up to 50,000 ft.
AeroVironment builds AeroVironment RQ-11 for usage by the United States military. It provides target information and real-time aerial observation, reconnaissance, and surveillance on any day. The craft weighs 4.2 lb., has a width of 4.5 ft., and a length of 3 ft. The UAS is motorized by Aveox 27/26/7-AV electric motor (Alex, 2022). The propellers are coupled into small engines, which transform the spinning movement from the power plant to a consistent forward motion making the propulsion effecter. The shaft rotation and blade pitch control constitute the control effectors. The UAS system operates at a range of 6.2 miles and a ceiling altitude of 150-1000 feet air-ground level. It has a flight endurance of approximately 60-90 minutes and a maximum airspeed of 26 mph.
Propulsion systems allow the aircraft to move from one place to another through forwarding motion or vertical lifts. These systems must be reliable and efficient to allow for greater endurance and enough power to ensure consistent operations and sustain their energy source. Being that the system is responsible for the control of the aircraft, during its examination, one should continually assess its mechanism of control.
References
Air Force. (2022). MQ-9 Reaper. Official the United States Air Force.
Alex, D. (2022). AeroVironment RQ-11 Raven. Military Factory.
Amici, C., Ceresoli, F., Pasetti, M., Saponi, M., Tiboni, M., & Zanoni, S. (2021). Review of propulsion system design strategies for unmanned aerial vehicles. Applied Sciences, 11(11), 5209.
Writer, S. (2018). Boeing Insitu RQ-21 Blackjack (Integrator).