The Turbomeca Turmo is a family of French turboshaft engines manufactured for helicopter use. Developed from the earlier Turbomeca Artouste, later versions delivered up to 1,300 kW (1,700 shp). A turboprop version was developed for use with the Bréguet 941 transport aircraft.
The Turmo was initially developed with a single-stage centrifugal compressor, annular combustion chamber and single stage turbine. Power output was from a single-stage free power turbine and was initially 200 kW (270 hp).[1]
During early post-war helicopter development, the use of cold and hot rotor tip-jets was widely investigated. To provide large mass-flow air for efficient operation of the tip-jets, Turbomeca developed a gas turbine driven gas producer, powered by the free power-turbine of the Turmo to deliver the required gas flow.[1]
Variants
Data from:-Jane's all the World's Aircraft 1957–58[1]
Turmo I
The initial version of the Turmo; max continuous gearbox output 200 kW (270 shp) at 3,000 rpm, at 33,750 rpm gas generator speed.
Turmo II
Developed version of the Turmo I; max continuous gearbox output 240 kW (320 shp) at 34,000 rpm gas generator speed.
Turmo III
With 2-stage free power-turbine, pressure ratio 5.7:1 ;Maximum shaft output 560 kW (750 shp), max continuous 450 kW (600 shp) at 33,400 rpm
Turboprop engine with two axial stages, one centrifugal compressor stage and two free power turbine stages, rated at 1,300 kW (1,800 hp) at 32,000 rpm.
