Optimal design of a Savonius turbine

摘要: Wind energy and efficiency are two key terms in finding a solution to the world’s increasing energy problems and the possible dangers of the climate warming. Available technical designs are not always suitable for low wind-speeds, urban surroundings and high installation densities. Systems derived from the Savonius turbine may be possible converters for such conditions, if they deliver a sufficient efficiency. The present study aims at investigating and improving the output power and the efficiency of the standard Savonius turbine. For this purpose, a modified design is considered, involving simultaneously new blade shapes, an obstacle plate shielding the returning blade and a flow deflector. After checking the impact of design modification, the optimum angle and position of these guiding plates and modified blade shape leading to the highest performance of the Savonius turbine are computed by optimization. This optimization is carried out by coupling an in-house optimization library (OPAL) with an industrial Computational Fluid Dynamics (CFD) code (here ANSYS-Fluent). The optimization process maximizes the output power coefficient and relies on Evolutionary Algorithms. A considerable improvement of the modified Savonius turbine performance (typically 58% relative increase of the power coefficient) has been finally obtained in this manner.