What does a turbine do in a jet engine?
Turbine: The turbine section is another series of rotating blades that are driven by high-pressure air leaving the combustor. The turbine blades catch the rapid airflow, and rotate to drive a spinning shaft that turns the fan and compressor at the front of the engine.
What are the advantages of a turboprop engine with a free turbine?
The chief advantage of the free turbine is that it reduces torque loads during engine start, since the start mechanism does not have to rotate the propeller and reduction gear, but only the compressor and its turbine.
What drives the compressor of a free turbine engine?
A typical free power-turbine engine has two independent counter-rotating turbines. One turbine drives the compressor, while the other drives the propeller through a reduction gearbox.
What is the difference between a free power turbine and a direct drive turbine?
Direct drive engines can only be pulled back about 4\% in flight, while most free turbine engines can reduce prop rpm 10-15\%. Free turbines are typically more efficient at low altitudes than direct drives. But direct drives perform better at high altitudes, and become more efficient than free turbines.
What is a free turbine engine?
A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine. This is opposed to the power being extracted from the turbine/compressor shaft via a gear box.
Where is turbine used?
Turbines are used in wind power, hydropower, in heat engines, and for propulsion. Turbines are extremely important because of the fact that nearly all electricity is produced by turning mechanical energy from a turbine into electrical energy via a generator.
What are the advantages of using a free turbine?
The advantage of the free turbine is that the two turbines can operate at different speeds, and that these speeds can vary relative to each other. This is particularly advantageous for varying loads, such as turboprop engines.
What does a free power turbine do?
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.
What are the two different sections in a free turbine engine?
What are the two basic sections of a turbine engine? The hot section and the cold section.
Why are turbines used?
The work produced by a turbine can be used for generating electrical power when combined with a generator. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached.
Is a turbine a heat engine?
In general, a steam turbine is a rotary heat engine that converts thermal energy contained in the steam to mechanical energy or to electrical energy.
What is a free-turbine turboshaft?
A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine.
What is the function of the turbine in a jet engine?
The turbine is at the heart of any jet engine with its primary task being to drive the compressor. As described previously without the compressor no mechanical work would be done on the fluid prior combustion and the thrust produced would only be a function of the chemical energy stored within the fuel.
What is the difference between fixed turbine and free turbine?
The fixed turbine has a mechanical connection from the gas generator (gas-turbine engine) to the reduction gear box and propeller. The free turbine has only an air link from gas generator to the power turbines. There is no mechanical link from the propeller to the gas turbine engine (gas generator).
How does a turbojet engine work?
Turbojet Engine. Most of the hot exhaust has come from the surrounding air.) Leaving the burner, the hot exhaust is passed through the turbine. The turbine works like a windmill. Instead of needing energy to turn the blades to make the air flow, the turbine extracts energy from a flow of gas by making the blades spin in the flow.