湍流强度对水平轴风力机尾迹速度恢复影响机理的实验研究
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摘要
为研究湍流强度对风力机尾流速度恢复的影响,采用高频PIV对均匀来流和格栅入流时风力机下游尾流数据进行采集。通过对比轴向速度、径向速度及雷诺剪切应力发现:均匀来流时轴向速度分层现象明显;叶尖涡将主流卷吸进入尾流区,但无法穿透附着涡区,附着涡相当于一个隔离带;雷诺剪切应力集中在叶尖涡和中心涡区,附着涡区基本为零。格栅入流时下游2.5倍风轮直径处尾流与主流基本融合,主流径向掺混从叶尖涡穿过附着涡渗透到中心涡区;剪切应力在中心涡和叶尖涡区明显增大,附着涡区存在正的峰值,且附着涡区成为叶尖涡和中心涡区的一个动量输送带。相关结论可为风电场优化布局提供指导,有助于揭示湍流强度影响风力机出力和速度亏损的原因。
In order to study turbulence effects on velocity recovery,the wake data of the wind turbine under uniform inflow and turbulent inflow were collected by utilizing the TR-PIV. By comparing axial velocity,radial velocity and Reynolds shear stress,the axial velocity delamination phenomenon is obvious;The tip vortex entrainment mainstream into the wake but fails to penetrate the bound vortex;The bound vortex is equivalent to a separation zone. Reynolds stress is concentrated in the tip vortex and central vortex and it is almost zero in the bound vortex under uniform inflow. Under turbulent inflow the wake merges with the mainstream in the 2.5 D downstream of the wind turbine,the tip vortex entrainment mainstream through the bound vortex to the central vortex. The shear stress increases significantly in the tip vortex and the central vortex,then it has a positive peak in the bound vortex. It shows the bound vortex conveys momentum between the top vortices and the central vortex. The conclusions can provide guidance for wind farm optimization and help to reveal the reasons of turbulence effects on the wind turbine output and velocity loss.
In order to study turbulence effects on velocity recovery,the wake data of the wind turbine under uniform inflow and turbulent inflow were collected by utilizing the TR-PIV. By comparing axial velocity,radial velocity and Reynolds shear stress,the axial velocity delamination phenomenon is obvious;The tip vortex entrainment mainstream into the wake but fails to penetrate the bound vortex;The bound vortex is equivalent to a separation zone. Reynolds stress is concentrated in the tip vortex and central vortex and it is almost zero in the bound vortex under uniform inflow. Under turbulent inflow the wake merges with the mainstream in the 2.5 D downstream of the wind turbine,the tip vortex entrainment mainstream through the bound vortex to the central vortex. The shear stress increases significantly in the tip vortex and the central vortex,then it has a positive peak in the bound vortex. It shows the bound vortex conveys momentum between the top vortices and the central vortex. The conclusions can provide guidance for wind farm optimization and help to reveal the reasons of turbulence effects on the wind turbine output and velocity loss.
引文
[1]Espana G,Aubrun S,Loyer S,et al.Wind tunnel study of the wake meandering downstream of a modelled wind turbine as an effect of large scale turbulent eddies[J].Wind Engineeringand Industrial Aerodynamcs 2012,101:24-33.
[2]Mo J O,Choudhry A,Arjomandi M,et al.Large eddy simulation of the wind turbine wake characteristics in the numerical wind tunnel model[J].Journal of Wind Engineering and Industrial Aerodynamics,2013,112(1):11-24.
[3]胡丹梅,田杰,杜朝辉.水平轴风力机尾迹流场PIV实验研究[J].太阳能学报,2007,28(2):200-206.[3]Hu Danmei,Tian Jie,Du Chaohui.PIV experimental study on the wake flow of horizontal-axis wind turbine model[J]Acta Energiae Solaris Sinica,2007,28(2):200-206.
[4]高志鹰,汪建文,东雪青,等.水平轴风力机近尾迹流场结构的实验研究[J].太阳能学报,2011,32(6):897-900.[4]Gao Zhiying,Wang Jianwen,Dong Xueqing,et al.Experimental investigation on near wake structure of horizontal axis wind turbine[J].Acta Energiae Solaris Sinica,2011,32(6):897-900.
[5]章书成,东雪青,汪建文,等.风力机尾迹速度场脉动特性的实验研究[J].工程热物理学报,2016,37(7):1432-1437.[5]Zhang Shucheng,Dong Xueqing,Wang Jianwen,et al.Experimental research on the pulsation characteristics of wind turbine wake velocity field[J].Journal of Engineering Thermophysics,2016,37(7):1432-1437.
[6]陈秋华,赖旭.基于SPIV的风力机叶尖涡与尾流流场相关性研究[J].太阳能学报,2016,37(2):297-302.[6]Chen Qiuhua,Lai Xu.SPIV analysis of correlation of tip vortex and wake flow of horizontal axis wind turbine[J].Acta Energiae Solaris Sinica,2016,37(2):297-302.
[7]Maeda T,Kamada Y,Murata J,et al.Wind tunnel study on wind and turbulence intensity profiles in wind turbine wake[J].Journal of Thermal Science,2011,20(2):127-132.
[8]Chu C R,Chiang P H.Turbulence effects on the wake flow and power production of a horizontal-axis wind turbine[J].Journal of Wind Engineering&Industrial Aerodynamics,2014,124(7):82-89.
[9]Mühle F,Adaramola M S,Sretran L.The effect of the number of blades on wind turbine wake-a comparison between 2-and 3-bladed rotors[J].Journal of Physics:Conference Series,2016,75(3):1-10.
[10]Talavera M,Shu F.Experimental study of turbulence intensity influence on wind turbine performance and wake recovery in a low-speed wind tunnel[J].Renewable Energy,2017,109:363-371.
[2]Mo J O,Choudhry A,Arjomandi M,et al.Large eddy simulation of the wind turbine wake characteristics in the numerical wind tunnel model[J].Journal of Wind Engineering and Industrial Aerodynamics,2013,112(1):11-24.
[3]胡丹梅,田杰,杜朝辉.水平轴风力机尾迹流场PIV实验研究[J].太阳能学报,2007,28(2):200-206.[3]Hu Danmei,Tian Jie,Du Chaohui.PIV experimental study on the wake flow of horizontal-axis wind turbine model[J]Acta Energiae Solaris Sinica,2007,28(2):200-206.
[4]高志鹰,汪建文,东雪青,等.水平轴风力机近尾迹流场结构的实验研究[J].太阳能学报,2011,32(6):897-900.[4]Gao Zhiying,Wang Jianwen,Dong Xueqing,et al.Experimental investigation on near wake structure of horizontal axis wind turbine[J].Acta Energiae Solaris Sinica,2011,32(6):897-900.
[5]章书成,东雪青,汪建文,等.风力机尾迹速度场脉动特性的实验研究[J].工程热物理学报,2016,37(7):1432-1437.[5]Zhang Shucheng,Dong Xueqing,Wang Jianwen,et al.Experimental research on the pulsation characteristics of wind turbine wake velocity field[J].Journal of Engineering Thermophysics,2016,37(7):1432-1437.
[6]陈秋华,赖旭.基于SPIV的风力机叶尖涡与尾流流场相关性研究[J].太阳能学报,2016,37(2):297-302.[6]Chen Qiuhua,Lai Xu.SPIV analysis of correlation of tip vortex and wake flow of horizontal axis wind turbine[J].Acta Energiae Solaris Sinica,2016,37(2):297-302.
[7]Maeda T,Kamada Y,Murata J,et al.Wind tunnel study on wind and turbulence intensity profiles in wind turbine wake[J].Journal of Thermal Science,2011,20(2):127-132.
[8]Chu C R,Chiang P H.Turbulence effects on the wake flow and power production of a horizontal-axis wind turbine[J].Journal of Wind Engineering&Industrial Aerodynamics,2014,124(7):82-89.
[9]Mühle F,Adaramola M S,Sretran L.The effect of the number of blades on wind turbine wake-a comparison between 2-and 3-bladed rotors[J].Journal of Physics:Conference Series,2016,75(3):1-10.
[10]Talavera M,Shu F.Experimental study of turbulence intensity influence on wind turbine performance and wake recovery in a low-speed wind tunnel[J].Renewable Energy,2017,109:363-371.