HYDRAULIC TURBINE WITH INTERBLADE VORTEX SUPPRESSOR

摘要

An improved Francis-type turbine runner. To extend operating range to partial load, inter blade fins partially extend into the flow paths between the runner blades. The inter blade fins correspond in shape and pattern with the shape and pattern of that portion of the runner blades with which the fins coextend along the flow paths between blades. The fins are recessed rearwardly of the flow dividing edges of the runner blades in the flow paths between the runner blades and reduce occurrence of inter blade vortices during partial or low load operating conditions. The shape of the interblade fins is further improved by tilting or sloping the tip of the interblade fin towards the suction surface of the adjacent blade. This creates a small convergence in the flow path between the fin and the suction surface of the blade.