海流发电翼形前缘轮廓对升阻力特性的影响
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摘要
利用海流能发电可为海洋监测锚系系统供电。发电装置叶片形状对发电效率有直接影响。目前还没有针对海流条件的海流能发电装置叶片翼形设计准则,大多参照风电叶片翼形。相对于风力环境,海流速度较低,密度较大。以NACA4409为例,着重探讨海流条件下圆形前缘翼形和两种椭圆形前缘翼形的前缘形状对运行状态的影响。采用k-ωsst湍流模型的仿真结果发现:与圆形前缘翼形相比,椭圆形前缘翼形可获得更高的升阻比;椭圆形前缘翼形长短轴比直接影响翼形的升阻力特性,且长短轴比不宜过大。理论分析结果对于海流发电装置叶片设计具有参考价值。
The ocean current power generator can provide power for mooring system. The shape of generator blades has a direct impact on generating efficiency. At present,there is no design criterion for the blade airfoil of current power generation device,most of which refer to the wind turbine blade airfoil. Compared with the wind environment,the current velocity is low and the density is relatively large. In this paper,NACA4409 is taken as an example to investigate the influence of the leading edge shapes of the circular leading edge airfoil and two elliptical leading edge airfoils on the operating conditions. The results of the k-ω sst turbulence model show that the elliptical leading edge airfoil can obtain higher lift-drag ratio than the circular leading edge airfoil. The ratio of long axis to short axis of elliptical leading edge blade has a direct impact on the lift and drag characteristics of the airfoil,and the ratio of long axis to short axis should not be too large. The theoretical analysis results have reference value for the design of the blades of ocean current generating units.
The ocean current power generator can provide power for mooring system. The shape of generator blades has a direct impact on generating efficiency. At present,there is no design criterion for the blade airfoil of current power generation device,most of which refer to the wind turbine blade airfoil. Compared with the wind environment,the current velocity is low and the density is relatively large. In this paper,NACA4409 is taken as an example to investigate the influence of the leading edge shapes of the circular leading edge airfoil and two elliptical leading edge airfoils on the operating conditions. The results of the k-ω sst turbulence model show that the elliptical leading edge airfoil can obtain higher lift-drag ratio than the circular leading edge airfoil. The ratio of long axis to short axis of elliptical leading edge blade has a direct impact on the lift and drag characteristics of the airfoil,and the ratio of long axis to short axis should not be too large. The theoretical analysis results have reference value for the design of the blades of ocean current generating units.
引文
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[2] MOLLAND A F. Measurements and predictions of forces,pressures and cavitation on 2-D sections suitable for marine current turbines[J]. Institution of Mechanical Engineers Part(M),2004,218(2):127-138.
[3] BAHAJ A S,BATTEN W M J,MCCANN G.Experimental verifications of numerical predictions for the hydrodynamic performance of horizontal axis marine current turbines[J]. Renewable Energy,2007,32(15):2479-2490.
[4] DAJANI S,SHEHADEH M,SAQR K M,et al.Numerical study for a marine current turbine blade performance under varying angle of attack[J].Energy Procedia,2017(119):898-909.
[5]吕彩霞.东海J断面上黑潮表层流速变化的初步分析[J].海洋湖沼通报,1983(1):9-14.
[6] LOUREIRO J B R,ALHO A T P,FREIRE A P S.The numerical computation of near-wall turbulent flow over a steep hill[J]. Journal of Wind Engineering&Industrial Aerodynamics, 2008,96(5):540-561.
[7] El-BEHERY S M,HAMED M H. A comparative study of turbulence models performance for separating flow in a planar asymmetric diffuser[J]. Computers&Fluids,2011,44(1):248-257.
[8] ANDERSON J D. Fundamentals of Aerodynamics[M]. McGraw-Hill,1984.