Influence of microcylinders with different vibration laws on the flow control effect of a horizontal axis wind turbine

摘要

Due to the flow separation on the blade of the NREL Phase VI wind turbine, a new flow control technique involving installation of an off-surface vibrating small structure is proposed. By considering the actual flow condition, fluid-solid coupling is applied in which two kinds of microcylinder vibration modes are set up, and the aerodynamic performance is numerically studied. The influence of the vibration modes, amplitude, and frequency of the off-surface vibrating small structure on the aerodynamic performance is explored. For various stall conditions, the flow separation can be well suppressed by utilizing a suitable vibrating microcylinder rather than a static microcylinder. In addition, the vibrating microcylinder shows a noticeable suppression effect on large flow separation. Both the vibration direction and vibration amplitude play leading roles in the improvement of the aerodynamic performance, and a microcylinder with a high vibration frequency can more quickly suppress surface flow separation to achieve an optimum aerodynamic performance than a microcylinder with a low vibration frequency. By setting microcylinders with suitable vibration rules close to the blade surface, the wind energy coefficient can be obviously increased compared with those obtained when adding a static microcylinder or without microcylinder addition.