FRANCIS TURBINE WHEEL Russian patent published in 2006 - IPC F03B3/02 

FIELD: hydroelectric stations and hydraulic drives.

SUBSTANCE: proposed device has blades with cylindrical surfaces arranged between rims. Generatrix of cylindrical surfaces is parallel to axis of hydraulic turbine and rises to axis of hydraulic turbine. Shape of blade of wheel is formed by angle of tilting of skeleton line of blade profile passing from larger part of blade profile changing according to linear dependence to constant profile on the rest of part and selection of parameters of wheel from the following relations: change of β according to linear dependence from β₁ to β₂ on larger part of blade profile at distance from D₁ to 1.01D₂, β=const=β₂ on the rest part from 1.01D₂ to D₂, range of rise of generatrix of blade surfaces from (0.08-0.20)D₁ at liquid inlet to wheel to (0.15-0.30)D₁ at outlet from wheel, D₂/D₁=(0.6-0.73) where D₁ is outer diameter of wheel; D₂ is inner diameter of wheel; D₂/D₁ is relative diameter of wheel; β is angle of tilting of skeleton line of blade profile; β₁ is angle of tilting of inlet element of skeleton line of blade profile to circumferential direction; β₂ is angle of tilting of outlet element of blade skeleton line.

EFFECT: enlarged range of operation of Francis turbine.

2 dwg