随着大型风电基地建设,上游风机在运行时会使下游风场风速下降,湍流度增大,造成下游风机发电功率降低,加剧风机的疲劳破坏并缩短其服役周期。因此,亟需开展风机尾流研究,明确其特性及演化规律。为了揭示不同入流及偏航角下的单风机尾流...随着大型风电基地建设,上游风机在运行时会使下游风场风速下降,湍流度增大,造成下游风机发电功率降低,加剧风机的疲劳破坏并缩短其服役周期。因此,亟需开展风机尾流研究,明确其特性及演化规律。为了揭示不同入流及偏航角下的单风机尾流特性,基于单风机尾流风洞试验,验证基于大涡模拟(Large Eddy Simulation,LES)结合致动线模型(Actuator Line Model,ALM)数值模拟方法的准确性;基于LES-ALM模拟方法研究入流风场(包括风速及湍流度)及偏航角对风机尾流特性的影响,阐明正负偏航角下单风机尾流的对称性。结果表明:随着背景湍流度的增大,风机尾流恢复速度加快;当入流条件相同时,风机设置正负对称偏航角,其尾流风速也表现出一定的对称性;风机偏航角越大,风机尾流膨胀宽度会逐渐减小,并降低尾流风速的亏损程度。展开更多
We use the Wind Farm Parameterization(WFP) scheme coupled with the Weather Research and Forecasting model under multiple resolution regimes to simulate turbulent wake dynamics generated by a real onshore wind farm and...We use the Wind Farm Parameterization(WFP) scheme coupled with the Weather Research and Forecasting model under multiple resolution regimes to simulate turbulent wake dynamics generated by a real onshore wind farm and their influence at the local meteorological scale. The model outputs are compared with earlier modeling and observation studies. It is found that higher vertical and horizontal resolutions have great impacts on the simulated wake flow dynamics. The corresponding wind speed deficit and turbulent kinetic energy results match well with previous studies. In addition, the effect of horizontal resolution on near-surface meteorology is significantly higher than that of vertical resolution. The wake flow field extends from the start of the wind farm to downstream within 10 km, where the wind speed deficit may exceed 4%. For a height of 150 m or at a distance of about 25 km downstream, the wind speed deficit is around 2%. This indicates that, at a distance of more than 25 km downstream, the impact of the wind turbines can be ignored. Analysis of near-surface meteorology indicates a night and early morning warming near the surface, and increase in near-surface water vapor mixing ratio with decreasing surface sensible and latent heat fluxes. During daytime, a slight cooling near the surface and decrease in the near-surface water vapor mixing ratio with increasing surface sensible and latent heat fluxes is noticed over the wind farm area.展开更多
文摘随着大型风电基地建设,上游风机在运行时会使下游风场风速下降,湍流度增大,造成下游风机发电功率降低,加剧风机的疲劳破坏并缩短其服役周期。因此,亟需开展风机尾流研究,明确其特性及演化规律。为了揭示不同入流及偏航角下的单风机尾流特性,基于单风机尾流风洞试验,验证基于大涡模拟(Large Eddy Simulation,LES)结合致动线模型(Actuator Line Model,ALM)数值模拟方法的准确性;基于LES-ALM模拟方法研究入流风场(包括风速及湍流度)及偏航角对风机尾流特性的影响,阐明正负偏航角下单风机尾流的对称性。结果表明:随着背景湍流度的增大,风机尾流恢复速度加快;当入流条件相同时,风机设置正负对称偏航角,其尾流风速也表现出一定的对称性;风机偏航角越大,风机尾流膨胀宽度会逐渐减小,并降低尾流风速的亏损程度。
基金the National Key Research and Development Program of China (Grant No.2017YFA0604501)the National Natural Science Foundation of China (Grant No.41475013) for the funding support
文摘We use the Wind Farm Parameterization(WFP) scheme coupled with the Weather Research and Forecasting model under multiple resolution regimes to simulate turbulent wake dynamics generated by a real onshore wind farm and their influence at the local meteorological scale. The model outputs are compared with earlier modeling and observation studies. It is found that higher vertical and horizontal resolutions have great impacts on the simulated wake flow dynamics. The corresponding wind speed deficit and turbulent kinetic energy results match well with previous studies. In addition, the effect of horizontal resolution on near-surface meteorology is significantly higher than that of vertical resolution. The wake flow field extends from the start of the wind farm to downstream within 10 km, where the wind speed deficit may exceed 4%. For a height of 150 m or at a distance of about 25 km downstream, the wind speed deficit is around 2%. This indicates that, at a distance of more than 25 km downstream, the impact of the wind turbines can be ignored. Analysis of near-surface meteorology indicates a night and early morning warming near the surface, and increase in near-surface water vapor mixing ratio with decreasing surface sensible and latent heat fluxes. During daytime, a slight cooling near the surface and decrease in the near-surface water vapor mixing ratio with increasing surface sensible and latent heat fluxes is noticed over the wind farm area.
