回転軸が傾斜した直線翼垂直軸風車の後流に対するアームの影響の数値解析

抄録

When considering a wind farm (or a tidal farm) consisting of lots of vertical axis turbines, in order to obtain the high power density (output/site area), it is very important to get the faster-recovery in flow speed of each rotor wake. Three-dimensional computational fluid dynamics analysis targeting a two-bladed vertical axis wind turbine (diameter: 0.75 m, height: 0.5 m) was conducted to investigate the effects of both the slant rotational axis and arms on the recovery of wake, under the condition of tip speed ratio of 3. The wake of the rotor with the slant rotational axis of 25° was recovered faster than that of the armless rotor. In the case without inclination, the wake recovery appeared to be almost the same between the rotors with and without the arms. In the case with inclination, however, the wake recovery of the rotor with arms was delayed in comparison with the armless rotor. In the case of axis-inclination of 25°, the vertical velocity component of 10% of the main flow was observed in the wake of the armless rotor; on the other hand, the rise in that component was suppressed to 5% in the wake of the rotor with arms.