Design considerations for an ultra-low-head Kaplan turbine system

Interests in utilizing small hydraulic systems are increasing recently, and new technology was developed worldwide. In comparison to large hydraulic systems which are normally equipped with a high dam and sizeable turbine system, small hydraulic has significant environmental and economic advantages. Most of the research focuses on small hydraulic systems that operating between a 2m-30m head condition or zero head hydraulic kinetic conversion system. However, the ultra-low head condition (head condition between 1m-3m) is another attractive, renewable and effective resource for developing a hydraulic system. Traditional hydraulic turbines like the Francis, Crossflow, and Kaplan turbines were all been modified and designed for small hydraulic systems. However, designing for ultra-low head (ULH) condition required some non-traditional design considerations which had not been yet proposed. This paper proposes several overall geometry design considerations for developing a ULH Kaplan turbine.