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Cascade view
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Meridional view
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Velocity Triangle for a turbine stage
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Triangle at section 3
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Equation of fluid motion
Conservation of mass
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Conservation to momentum
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Rothalpy in stators and rotors
Stators:
Rotors:
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Relative stagnation enthalpy
Efficiency and Reaction
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Coefficients for axial machines
Flow coefficient
Stage loading coefficients or work coefficients
Efficiency
Reaction
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Reaction for repeating stage
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Impulse and 50% Reaction
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Impulse
R=0
50% Reaction
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Loading and Efficiency Variation with reaction
Impulse
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50% Reaction
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Stage efficiency in impulse and reaction
Entropy generation
1.
Viscous friction in either boundary or free shear layers.2. Heat transfer across a finite temperature difference
3. Non-equilibrium processes such as occur in shock waves.
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Number of stages in a turbine section
Available energy per stage depends on the stage
reaction, rotor mean diameter and rotor speed:
Impulse Stage:
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50% Reaction:
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Fluid Flow
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Flow Function
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Critical pressure ratio
= Superheated steam (0.546)
= Saturated Steam(0.577)
LP Turbine exit velocity :1300-1400 ft/sec(396-
426m/s)
HP Inlet 1000F(537C) 1800-3500PSI(125-241bar):
2100-2200 ft/sec(640-670 m/s)
