数値解析を用いたウグリンスキー型風車の性能評価

抄録

Performance improvements in Vertical Axis Wind Turbines (VAWTs) are expected for small-scale power sources. The Savonius wind turbine, which is a representative example of VAWTs, is characterized by various advantages such as simple design, independence of wind direction, and small footprint. However, due to generation of a negative torque by the returning blade the Savonius model suffers from low efficiency. The Ugrinsky wind turbine allegedly produces higher output than the traditional Savonius turbine, yet any recent studies cannot be found. Thus, investigation on the Ugrinsky wind turbine was conducted, and the evaluation was carried out by comparing it to the Savonius wind turbine. The flow around the turbine was simulated by using the regularized lattice Boltzmann method. The virtual flux method was used to describe the shape of the turbine on a Cartesian grid, and the multi-block method was used for local fine grids of the turbine. The rotational speed of the turbine was maintained constant, and its performance was evaluated by the output power and torque coefficients. The results show that the Ugrinsky model achieves a higher power coefficient value by 43.2% compared to that of the Savonius model. Furthermore, unlike the Savonius model, the Ugrinsky counterpart maintained a positive torque coefficient value throughout a cycle at the tip speed ratio of 0.5.