Numerical investigation of the torque produced by Darrieus vertical axis wind turbine in dusty flow

Abstract

In this study, the performance of a Darrieus vertical axis wind turbine in a dusty flow is investigated. First, the maximum torque generated at different blade tip speed ratios (TSRs) is studied. After determining the maximum torque of the turbine in a single-phase model, the problem is converted to a two-phase model, and the performance of the turbine is investigated. The performance of the wind turbine in the dusty flow is compared with that of the flow without sand particles at different TSRs. The volume fraction of the two-phase model (air-particles) is 10⁻⁶, and the diameter of the particles is 100 μm. The maximum torque and average power coefficients were determined for both single-phase and two-phase flows at a TSR of 2.4. It was found that the torque and power coefficient of the turbine were affected by the discrete phase (particles), and their maximum values decreased from 0.190 and 0.456 to 0.142 and 0.340 (25 % decrease), respectively. In addition, wind speed is known to be the most important parameter affecting wind turbine performance. At high wind speeds, the negative effects of particles on the wind turbine are much greater. For example, at a TSR of 1.3 and a free flow velocity of 16.2 m/s, the negative effect of particles was 60 %, while at a TSR of 6 and a free flow velocity of 3.6 m/s, it dropped to 16 %. The present results can be used for the same conditions of a dusty flow around a Darrieus vertical axis wind turbine.