Contents
How does a turboprop reverse thrust?
Propeller-driven aircraft generate reverse thrust by changing the angle of their controllable-pitch propellers so that the propellers direct their thrust forward. Piston-engine aircraft tend not to have reverse thrust, however turboprop aircraft generally do.
What are three of the forces or pressures that can be used to change the blade angle of a constant speed propeller?
Three factors tend to vary the r.p.m. of the engine during operation. These factors are power, airspeed, and air density. If the r.p.m. is to maintain constant, the blade angle must vary directly with power, directly with airspeed, and inversely with air density.
How does a turboprop propeller work?
The turboprop uses a gas turbine core to turn a propeller. As mentioned on a previous page, propeller engines develop thrust by moving a large mass of air through a small change in velocity. Propellers are very efficient and can use nearly any kind of engine to turn the prop (including humans!).
Where is the condition lever on a turboprop?
A Condition Lever is a pilot actuated control which is located within the throttle quadrant of a turboprop engine equipped aircraft.
How does the compressor work in a turboprop engine?
As the hot, high-speed air flows over the turbine blades, they extract energy from the air, spinning the compressor turbine around in a circle, and turning the engine shaft that it’s connected to. This is the same shaft that the compressor section and all engine driven accessories are connected to.
Where is the propeller located in a turboprop engine?
While the compressor turbine may be spinning the aft portion of the engine shaft (compressor section and engine driven accessories) at more than 37,000 RPM, it is NOT spinning the propeller. An entirely separate second engine shaft is located just forward of the compressor turbine.
How is propulsive efficiency of a turboprop determined?
Propulsive efficiency comparison for various gas turbine engine configurations. Exhaust thrust in a turboprop is sacrificed in favour of shaft power, which is obtained by extracting additional power (up to that necessary to drive the compressor) from turbine expansion.