Turbo-compound engine

The Napier Nomad engine. The power-recovery turbine sits underneath a two-stroke diesel engine.

A turbo-compound engine is a reciprocating engine that employs a turbine to recover energy from the exhaust gases. Instead of using that energy to drive a turbocharger as found in many high-power aircraft engines, the energy is instead sent to the output shaft to increase the total power delivered by the engine. The turbine is usually mechanically connected to the crankshaft, as on the Wright R-3350 Duplex-Cyclone, but electric and hydraulic power recovery systems have been investigated as well.

As this recovery process does not increase fuel consumption, it has the effect of reducing the specific fuel consumption, the ratio of fuel use to power.[1] Turbo-compounding was used for commercial airliners and similar long-range, long-endurance roles before the introduction of turbojet engines. Examples using the Duplex-Cyclone include the Douglas DC-7B and Lockheed L-1049 Super Constellation, while other designs did not see production use.

  1. ^ Stimson, Thomas E., Junior (February 1956). "The Race of the Airliners". Popular Mechanics: 113–118. Retrieved 19 February 2016.{{cite journal}}: CS1 maint: multiple names: authors list (link)