Convertible composite engine

TLDR: A convertible composite engine capable of either shaft horsepower or thrust generation and split-powered operation in which partial thrust and partial shaft horsepower is generated is described in this article, where the engine is concentric about a single centerline and includes two coaxial free turbines, one driving a bypass fan and the other a shaft horsepower take-off, such as is commonly used to drive a helicopter rotor drive shaft.

Abstract: A convertible composite engine capable of either shaft horsepower or thrust generation and split-powered operation in which partial thrust and partial shaft horsepower is generated. The engine is concentric about a single centerline and includes two coaxial free turbines, one driving a load such as by-pass fan and the other a shaft horsepower take-off, such as is commonly used to drive a helicopter rotor drive shaft. A single gas generator provides compressed and heated gases to the coaxial free turbines with the total amount of gases provided determined by the total power required from the two free turbines and the split of gas flow through each free turbine determined by the position of the variable inlet guide vanes at the inlet to each turbine.