What is the function of a reduction gear for a turbine?
However, the effective functioning of a propeller requires a relatively low rpm range. For this reason, a reduction gear is used, which reduces the high speed motion of the steam turbine into low rpm range required by the propeller.
Why do turbines have less stages than compressors?
Very simply, a turbine has fewer stages than the compressor, because the flow in the turbine is going in the direction of reducing pressure – the air wants to go that way naturally. But a compressor has to make the air flow in the direction of increasing pressure.
Why does a compressor of an aircraft engine has more number of stages compared to a turbine section?
They partially convert high velocity air into high pressure. Each consecutive compressor stage compresses the air even more. The number of stages is determined by the amount of air and total pressure rise required. The greater the number of stages, the higher the compression ratio.
Why is it necessary to couple the fan to the turbine with a gearbox?
The way this gets solved is using a gearbox, as it allows the turbine power to be used at a high enough torque to spin the fan without stalling the engine, and at a low enough rotational speed to avoid the blade going supersonic.
What does reduced gear mean?
Definition of reduction gear : a combination of gears used to reduce the input speed (as of a marine turbine) to a lower output speed (as of a ship’s propeller)
Where are reduction gearboxes used?
Reduction drives are used in engines of all kinds to increase the amount of torque per revolution of a shaft: the gearbox of any car is a ubiquitous example of a reduction drive. Common household uses are washing machines, food blenders and window-winders.
Why are there more stages in the compressor than the turbine?
More compressor stages is needed to achieve a higher compression ratio. More stages equals higher final pressure rise. Normally, a single stage in an axial flow compressor gives a very low pressure rise (a ratio of 1.2:1) which has been already explained quite well in one of the answers.
What is the difference between compressor blade and turbine blade?
Note also that a compressor blade takes mechanical energy and converts it to flow and pressure, while a turbine blade does the reverse. So the shapes are different. The compressor blade usually is cold and the turbine blade (in a jet engine) is very hot. So the materials are different.
What is the function of compressor in gas turbine?
There are several different types of gas turbine engines, but all turbine engines have some parts in common. All turbine engines have a compressor to increase the pressure of the incoming air before it enters the combustor. Compressor performance has a large influence on total engine performance.
How does a compressor work in a jet engine?
A compressor raises the pressure of the air. The compressor is made with many blades attached to a shaft. The blades spin at high speed and compress or squeeze the air. The compressed air is then sprayed with fuel and an electric spark lights the mixture.
What is the difference between turbofan and turbojet?
Unlike a turbojet that sucks in all the air inside the engine, a turbofan engine sports a large fan at the front which sucks in most of the airflow around the outside of the engine. This makes the engine quieter and more thrust at low speeds. A majority of all the airliners are powered by this engine.
What is the difference between turbofan and turboprop?
The fundamental difference lies in how the remaining exhaust energy is used. Turboprops extract virtually all of the kinetic energy and a larger portion of the thermal energy via expansion turbines to drive the propeller, while turbofans utilize an expansion nozzle to create high speed exhaust (thrust).
What are the effects of dirt on the compressor blades?
Accumulation of dirt on the compressor blades reduces the aerodynamic efficiency of the blades with resultant deterioration in engine performance. The efficiency of the blades is impaired by dirt deposits in a manner similar to that of an aircraft wing under icing conditions.
What happens when an air compressor bogs down?
The compressor motor begins to labor, the compressor motor slows, the sound changes, and the buildup of air pressure in the tank either stops completely, or slows substantially. Sometimes, when an air compressor bogs down, that process causes a problem with the power. The motor may pull too many amps, and the circuit breaker lets go.
Why is the compressor on a wind turbine important for maintenance?
Maintenance of the compressor, or cold section, is one of concern because damage to blades can cause engine failure. Much of the damage to the blades arises from foreign matter being drawn into the turbine engine air intakes. The atmosphere near the ground is filled with tiny particles of dirt, oil, soot, and other foreign matter.
Why is there a relief valve in a compressor?
This type of ” compressor” cannot have its output closed as it would cause mechanical disintegration of the units, so a dump or relief valve is included in the circuit. In air compressors there is a relief valve in the buffer tank to control the maximum built up pressure, as the buffer tank could explode.
https://www.youtube.com/watch?v=hH_M_mAa6wQ