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Radial Inflow turbines
These turbines provide greateramount of work per stage, ease ofmanufacture, andRuggedness. Efficiency is equal to thebest of those of axial turbines.
Main disadvantage is requirement ofadvanced techniques for rotor coolingand shockresistance
Commonly used in automobileturbochargers and helicopters, andexpanders fro cryogenicprocesses and liquefaction of gases.
1. Cantilever turbine
Radial Flow Gas Turbines
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There is zero incidence flow due to thedirection of the relative velocity whichmakes this an inward flow turbine.
Working principle is the reverse of acentrifugal compressor with differentimpeller shapes.
1. 90° IFR (Centripetal) Turbine
Radial Flow Gas Turbines
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Hydraulic turbines – The Pelton Turbine
A Multi-nozzle Pelton
turbine
The velocity triangle
x 1064 6 8 10 12 14
0,65
0,7
0,75
0,8
0,85
0,9
0,95
head (bar)
Effic
ienc
y (-)
h p elton2h p elton2
h p elton1h p elton1
h cumulth cumult
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Hydraulic turbines – The Pelton Turbine
A common Pelton Turbine efficiency trend
with the blade – jet speed ratio
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Hydraulic turbines – The Pelton Turbine
Sizing the penstock with Darcy’s Equation
f= friction factor (recall Moody diagram)l = Length of the piped= pipe diameterV=Average fluid velocity in the pipe
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Hydraulic turbines – Francis Turbine
Inlet-exit velocity triangles
Comparison of velocity triangles
Comparison of
efficiencies