Lab Testing and Modeling of Archimedes Screw Turbines
Archimedes Screw Turbines (ASTs) are being utilized across Europe and are beginning to be utilized in North America for micro-hydropower (less than 500 kW) production. There is currently no mathematical model in the literature which describes the power production of an AST of arbitrary geometry and at partial-fill conditions, and only limited literature on laboratory and full-scale testing of AST performance. A custom lab test apparatus for scale-model ASTs was developed, and five different scale model ASTs were tested to quantify performance in terms of power production. In addition, testing was performed on a small prototype AST installed on a waterway in Ontario. A quasi-static numerical model is presented which describes the performance of an arbitrary AST at normal operating conditions, including varying rotation rates, flows, and fill levels. The model uses the laboratory and prototype test data for validation. Under normal operating conditions the model accurately predicts AST power production. Some limitations exist in the model regarding accurately quantifying leakage through the turbine, as well as operation at very low fill levels.