Influence of Angle of Slope of Blades on Operation of Centrifugal Turbine

Abstract

The velocity of a fluid in the impeller of a centrifugal (radial-flow) turbine and the energy of the fluid flow which it absorbs are analyzed as a function of the angle of slope of the blade (which is assumed to be constant). The blades of the impeller absorb the kinetic energy of the flow, which is expended in rotation of the impeller and is determined by Euler’s equation. One-half the energy of the fluid is expended in rotation of the impeller and in varying the direction of the fluid, while the other half is expended in overcoming the action of centrifugal force, which reduces the rate of flow of the fluid through the impeller. The maximal flow rate of the fluid is achieved with an angle of slope of the blades of 45° while the maximal power transmitted by the fluid to rotate the turbine is attained at an angle of 60°.