Performance Characteristics of Kaplan Turbine

A Kaplan Turbine is
What is the range of speed ratio Ku for a Kaplan Turbine for its most efficient operation?
Velocity of runner of a Kaplan turbine at inlet(Vf1) and outlet (Vf2) are
For low head and high discharge, the hydraulic turbine used is
What is the range of Flow ratio for a Kaplan turbine for its most efficient operation?