A RUNNER BLADE FOR LOW SPECIFIC SPEED FRANCIS TURBINE.

摘要

The present invention relates to design of new runner to suit an existing Francis turbine water path. It is designed to meat performance at reduced head hence suitable for higher unit discharge and unit speed than originally designed. The blade of runner comprises a set of nine profiles covering crown to skirt and the profiles have distinct geometrical parameters. Computational fluid dynamic (CFD) based studies exhibit that the runner has better performance features for existing water path; both in terms of efficiency of pressure distribution for a rang of unit discharge q11=170-240 liters/second and unit speed n11=56-72 rpm; or alternatively for specific speed ranges ns, m=83-98.