free power turbine

free power turbine

An arrangement in which a turbine, or stage of turbines, in a gas turbine engine does not drive the compressor. Free turbines are used to drive the reduction gears for the propeller in a turboprop engine or the transmission and rotor of a helicopter. Also known as a power turbine or a free turbine. In a turbine engine, a turbine wheel drives the output shaft and is not connected to the shaft driving the compressor.