Investigation of the α angle's effect on the performance of an Archimedes turbine

Archimedes turbine is suitable to operate under low head (< 5 m) and in a wide range of discharge conditions. However, one of the problems in the implementation of Archimedes turbines is the optimum α angle values because several studies have yielded different results. The present study investigated the α angle's effect on an Archimedes turbine's performance by experimental method. The experimental method was chosen to determine the output power generate and to study the phenomenon of overflow leakage losses in the energy conversion process. The experiment was conducted with a discharge of 0.00106 m ³ /s, an α angle between 36 ⁰ until 44 ⁰ , and three different loads. Based on the experiment results, the higher α angle generated more power but less turbine efficiency; this was because the value of the effective head increased, which also increased the available power. This proved that the α angle does not heavily influence the amount of power generated. In addition, the prediction that overflow causes loss when the angle α increases was found to be inaccurate because it was influenced more by the load value than the α angle value. Thus, the α angle does not greatly affect the performance of turbine.