# ใช้ Francis turbine อธิบาย Theory Rotodynamic machine

## Presentation on theme: "ใช้ Francis turbine อธิบาย Theory Rotodynamic machine"— Presentation transcript:

ใช้ Francis turbine อธิบาย Theory Rotodynamic machine
Reaction Turbines ใช้ Francis turbine อธิบาย Theory Rotodynamic machine

Free Vortex Theory V1 cos a1 –U1=Vr1 cot β1 B b1 α1 Vrel1 U1 V1 Vrel1
Best Efficiency V1 V1 cos a1 Vr1 R1 R2 V2 T =ρQ (V1 r1 cos a1 – V2 r2 cos) a1 T ≈ ρQV1 r1 cos a1 Q= (2πR1 B) Vr1 = (2πR2 B) Vr2

V1 cos a1 –U1=Vr1 cot β1 Q= (2πR1 B) Vr1 α1 = 17.4o
Example 8.9 Roberson et al A Francis turbine is to be operated at a speed of 600 rpm and with the discharge 4.0 m3/s. If r1 = 0.60 m, β1 = 110o, and the blade height is 10 cm, what should be the guide vane angle α1 for a non-separating flow condition at the runner entrance? V1 cos a1 –U1=Vr1 cot β1 Q= (2πR1 B) Vr1 U1 = ωR1 = 37.7 s α1 = 17.4o

Find Torque T ≈ ρQV1 r1 cos a1 T = 81.2 kN-m Find Power P=Tω P = 5100 kw (Assume no loss ? Friction)

Axial Flow Turbine

Runners of Axial Flow Turbines

Mixed Flow Turbine