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Why pelton turbine is called as impulse turbine?
Water is blasted at the buckets one by one or more jets mounted in the surroundings casing. Momentum is transferred from water to buckets and a torque is created, causing the wheel to rotate. That's why it is an impulse turbine.
Why tripping value of axial shift of steam turbine is more than turbine rotor float?
axial shift depends upon the gap between rotot blade and fixed blade , not on float
How do turbines work?
A simple turbine.Air is drawn into the engine continuously and compressed by a series of rotating blades. Fuel is sprayed into the combustion chamber and burnt increasing the gas temperature to around 1200C.The hot high pressure gas expands through a second set of blades mounted on the same shaft as the compressor blades. The energy of the gas is partially expended powering the compressor, but has a residual energy which is either expended as a hot jet (resulting in thrust) or which drives a further independent set of blades to power a propeller or other device.see http://www.rolls-royce.com/education/schools/how_things_work/journey02/index.html
What are the advantages of free turbine engine over gas turbine engine?
A gas turbine engine will usually yield more power by weight than a piston engine. Main downside is that it can't be throttled very well. Energy efficiency isn't all that good to start with, and will drop right down if it has to be operated outside its optimum range.
What is eddies in volute casing of a centrifugal pump?
In Volute Casing, area of flow increases gradually, Due to this, the amount of movement of water opposite to the general flow of water is more. This movement of water against the actual flow of water is called EDDIES in Volutes casing of Centrifugal pump.Where as in Vortex casing area of flow is uniform and effect of formation of eddies is very less.
What is expansion turbine?
differential expansion is refer to differential distance between rotor blade and fix blade.rotor expand toward generator and casing expand toward control valve.when temperature increase ,expansion in casing and rotor.so rotor mass is less than casing which rotor expand more than casing.
What is positive differential expansion of steam turbine?
Differential expansion means gap between fixed Blade & rotating blase of a turbine.. When steam enters into the turbine, rotor tends to expand towards generator side & casing tends to expand towards control valve side. If differential expansion increase then there is a possibility of reducing axial gap between rotor & fixed blades. When differential expansion is positive its means rotor expand more than the casing expansion. There is a limit upto +ve 5. If increases than +ve 5 it means we have to check front side tie rods status.
Why pelton turbine is called as impulse turbine?
Water is blasted at the buckets one by one or more jets mounted in the surroundings casing. Momentum is transferred from water to buckets and a torque is created, causing the wheel to rotate. That's why it is an impulse turbine.
Why tripping value of axial shift of steam turbine is more than turbine rotor float?
axial shift depends upon the gap between rotot blade and fixed blade , not on float
What is the difference between isentropic and isenthalpic expansion?
isenthalpic expansion is through PRDS or control valve where entropy changes. Whereas expansion through a steam turbine is isentropic one and enthalpy drops. isentropic expansion is more efficient process as compared to isenthalic one.
What is helicopter rotor droop?
Helicopters fly by means of an angle of attack increase in the main - rotor disc. However - when this angle of attack increases, the drag experienced on the blades also increases which tends to want to slow the blades down. To avoid that, a gas turbine helicopter engine will have what is called a Power Turbine Governor or PTG. This control unit senses increases in torque values when the pilot pulls up on collective and distributes more fuel into the engine in order to get more output to counter the increase in drag on the rotor blades, thus maintaining a constant rotor RPM in all operating conditions. Rotor 'droop' is when the rotor RPM drops below a minimum given parameter and can be caused by a variety of problems.
Why more energy is produced if the turbine blade of a wind turbine is longer?
no
What are some major improvements of the helicopter over the years?
They are possibly too numerous to list, but some were getting more flexible rotors, fitting turbine engines, and most recently -anti vibration rotor hubs.
What is critical speed of steam turbin?
Answer:Turbine shaft material has its own natural frequency, when turbine rotates on such a speed that frequency of shaft become close to its natural frequency, machine causes noise & high vibrations because of resonance due to matching of frequency. Running of Steam "TURBINE" on this speed is avoided & this is called Critical speed. A turbine may have more then one critical speed, which may depend upon number of couplings.A second critical speed is when the Turbine blade tips approach the speed of sound. This effectively limits the speed of a turbine and explains why power plants tend to have turbines of the same capacity.Critical speed of the turbine is the rotor speed at which natural frequency of the assembled rotor (rotor shaft with discs, blades, shrouding strips etc in assembled condition) becomes equal to the operating speed. This is usually a expressed as a range (critical speed range).There are multiple critical speeds. However, the operating speed of the turbine may be above or below the first / lowest critical speed. Accordingly it is called as a flexible or a rigid rotor.Venkatesh
What is the impulse turbine mechanism?
Impulse turbine Mechanism deals with the Impluse force action-reaction . As we all know the Netwon 3rd law of motion," Every action has equal and opposite reaction", the same is work on this. As the water fall on the blade of the rotor it generate the impact force on the blade surface, The blade tends to give the same reaction to the fluid, but the rotor is attached to the rotating assembly, it absorb the force impact and give the reaction in the direction of the fluid flow.Thus the whole turbine rotates. The rotation speed of the turbine depends on the fluid velocity, more the fluid velocity, greater the rotation speed, ans greater the speed means more power generation. regards, Alpesh Prajapati india. BE Mech. (alpesh_engg@yahoo.co.in)
How do turbines work?
A simple turbine.Air is drawn into the engine continuously and compressed by a series of rotating blades. Fuel is sprayed into the combustion chamber and burnt increasing the gas temperature to around 1200C.The hot high pressure gas expands through a second set of blades mounted on the same shaft as the compressor blades. The energy of the gas is partially expended powering the compressor, but has a residual energy which is either expended as a hot jet (resulting in thrust) or which drives a further independent set of blades to power a propeller or other device.see http://www.rolls-royce.com/education/schools/how_things_work/journey02/index.html
When two or more turbine wheels are used in a jet engine what is placed in front each turbine wheel?
turbine stator (nozzle diaphragm)
