3 Free Vortex Theory V1 cos a1 –U1=Vr1 cot β1 B b1 α1 Vrel1 U1 V1 Vrel1 Best EfficiencyV1V1 cos a1Vr1R1R2V2T =ρQ (V1 r1 cos a1 – V2 r2 cos) a1T ≈ ρQV1 r1 cos a1Q= (2πR1 B) Vr1 = (2πR2 B) Vr2
4 V1 cos a1 –U1=Vr1 cot β1 Q= (2πR1 B) Vr1 α1 = 17.4o Example 8.9 Roberson et alA Francis turbine is to be operated at a speed of 600 rpmand with the discharge 4.0 m3/s.If r1 = 0.60 m, β1 = 110o, andthe blade height is 10 cm,what should be the guide vane angle α1for a non-separating flow condition at the runner entrance?V1 cos a1 –U1=Vr1 cot β1Q= (2πR1 B) Vr1U1 = ωR1 = 37.7 sα1 = 17.4o
5 Find TorqueT ≈ ρQV1 r1 cos a1T = 81.2 kN-mFind PowerP=TωP = 5100 kw(Assume no loss ? Friction)
Your consent to our cookies if you continue to use this website.