Hybrid UAV Engines

Hybrid UAV (unmanned aerial vehicle) and drone engines combine a piston-driven or Wankel combustion engine with an electric motor. They are designed to take advantage of the conversion of high energy density fuels such as gasoline, diesel and heavy fuel into electrical energy.

SP-180 SRE Hybrid Wankel UAV Engine by Sky Power International

Applications

In this way, drones equipped with hybrid engines can overcome the flight time limitations of systems powered solely by batteries. Hybrid drone engines are thus highly suited to long-range applications such as heavy cargo transport, surveillance, and mapping, assuming the aircraft is large enough to support the engine.

Typical Configuration of Hybrid Engines for Drones

There are two main configurations for hybrid drone powertrains. The first involves using the engine solely as a generator. The constant output of the generator is used to keep a battery charged, and this battery is used to power the drone rotors and all other important subsystems. This is a relatively simple design and results in fewer emissions than a purely engine-driven aircraft, as in this case, the engine is operating at a steady rate regardless of what the aircraft is doing.

RW1-300C Hybrid Engine for Drone by UAVHE

The second method connects both the motor and the engine to the propulsion system. The engine is used to supply power for takeoff and other peak thrust maneuvers that would drain the battery extremely quickly. During cruising, the motor can be used to power the UAV, and the engine also provides recharging of the battery. This method is more efficient and produces overall less noise, as electric motors are quieter than engines.

Advantages of Hybrid UAV Engines

In addition to the de-emphasis on the importance of batteries, hybrid UAV engines provide a number of other advantages. The use of a dual power source provides redundancy, improving the safety and reliability of the UAV. The battery can also be used for self-starting the engine or restarting it during flight.