Performance Model of Archimedes Screw Hydro Turbines with Variable Fill Level

AbstractArchimedes screw generators (ASGs) are beginning to be widely adopted at low-head hydro sites in Europe due to their high efficiency, competitive costs, and low environmental impact. ASGs are particularly appropriate for low-head sites. Power is transferred from a water flow to an Archimedes screw by the distribution of static pressure produced by the water volumes between the flights of the screw. Two theoretical models based on quasi-static pressure analysis are developed to predict the performance of ASGs. The first model uses idealized geometry, while the second incorporates the geometric properties of a rotating Archimedes screw, including slope, pitch, and inner and outer diameter. The second model was also formulated to simulate the performance of Archimedes screws operating across a full range of fill levels from empty to overfull. Both models predict that if all friction losses and entry and exit effects are neglected, the Archimedes screw can convert all potential energy in a water flow ...