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Axial turbine
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Axial turbine
In turbomachinery, an axial turbine is a turbine in which the flow of the working fluid is parallel to the shaft, as opposed to radial turbines, where the fluid runs around a shaft, as in a watermill. An axial turbine has a similar construction as an axial compressor, but it operates in the reverse, converting flow of the fluid into rotating mechanical energy.
A set of static guide vanes or nozzle vanes accelerates and adds swirl to the fluid and directs it to the next row of turbine blades mounted on a turbine rotor.
The angles in the absolute system are noted by alpha (α) and the angles in the relative system are noted by beta (β). Axial and tangential components of both absolute and relative velocities are shown in the figure. Static and stagnation values of pressure and enthalpy in the absolute and relative systems are also shown.
It is often assumed that the axial velocity component remains constant through the stage. From this condition we get: Also, for constant axial velocity yields a useful relation:
A single-stage impulse turbine is shown in Figure
There is no change in the static pressure through the rotor of an impulse machine. The variation of pressure and velocity of the fluid through the stage is also shown in Figure.
The absolute velocity of the fluid increases corresponding to the pressure drop through the nozzle blade row in which the only transformation of energy occurs. The transfer of energy occurs only across the rotor blade row. Therefore, the absolute fluid velocity decreases through this as shown in the figure. In the absence of any pressure drop through the rotor blades, the relative velocities at their entry and exit are the same for frictionless flow. To obtain this condition the rotor blade angles must be equal. Therefore, the utilization factor is given by
When the pressure drop available is large, it cannot all be used in one turbine stage. A single-stage utilizing a large pressure drop will have an impractically high peripheral speed of its rotor. This would lead to either a larger diameter or a very high rotational speed. Therefore, machines with large pressure drops employ more than one stage.
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Axial turbine AI simulator
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Axial turbine
In turbomachinery, an axial turbine is a turbine in which the flow of the working fluid is parallel to the shaft, as opposed to radial turbines, where the fluid runs around a shaft, as in a watermill. An axial turbine has a similar construction as an axial compressor, but it operates in the reverse, converting flow of the fluid into rotating mechanical energy.
A set of static guide vanes or nozzle vanes accelerates and adds swirl to the fluid and directs it to the next row of turbine blades mounted on a turbine rotor.
The angles in the absolute system are noted by alpha (α) and the angles in the relative system are noted by beta (β). Axial and tangential components of both absolute and relative velocities are shown in the figure. Static and stagnation values of pressure and enthalpy in the absolute and relative systems are also shown.
It is often assumed that the axial velocity component remains constant through the stage. From this condition we get: Also, for constant axial velocity yields a useful relation:
A single-stage impulse turbine is shown in Figure
There is no change in the static pressure through the rotor of an impulse machine. The variation of pressure and velocity of the fluid through the stage is also shown in Figure.
The absolute velocity of the fluid increases corresponding to the pressure drop through the nozzle blade row in which the only transformation of energy occurs. The transfer of energy occurs only across the rotor blade row. Therefore, the absolute fluid velocity decreases through this as shown in the figure. In the absence of any pressure drop through the rotor blades, the relative velocities at their entry and exit are the same for frictionless flow. To obtain this condition the rotor blade angles must be equal. Therefore, the utilization factor is given by
When the pressure drop available is large, it cannot all be used in one turbine stage. A single-stage utilizing a large pressure drop will have an impractically high peripheral speed of its rotor. This would lead to either a larger diameter or a very high rotational speed. Therefore, machines with large pressure drops employ more than one stage.