峡道潮流能提取远场水动力影响数值分析
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摘要
以群岛海域典型峡道——龟山水道为例,在验证良好的平面二维潮流数学模型的基础上,采用等效阻力法概化发电机组的近区影响,对不同潮流能提取功率系数条件下的区域远场潮流进行了模拟计算.从水位、流速时空变化及平均潮流能功率密度变化等方面分析了峡道潮流能提取对周围海域远场水动力的影响.模拟计算显示,发电机功率系数取0.5时影响比0.3时大,但影响基本局限在5km范围内;2种情况下,周围海域水位的变化都在5cm以内;潮周期内,急流时刻流速影响最大;机群内部及上下游流速都减小,而机群两侧及邻近水道流速会增大;平均功率密度的减小沿机群周围分布,且偏向于优势流方向,同时机群两侧和邻近水道平均功率密度会增大.
Based on a well-verified 2Dmathematical model for tidal current,the tidal current fields with two different power extraction schemes are simulated,where the presence of tidal current turbines is included as an additional bed friction source term.Guishan Channel,which is in a sea with many islands,is taken as a typical area where tidal current energy is extracted.The changes of water level,current velocity and mean tidal current power density are analyzed to study the far-field hydro-dynamic impact of tidal current energy extraction.The simulated results illustrate that the first scheme with a power coefficient 0.3is found to have lower impact on original flow than the second scheme(the power coefficient equals 0.5).In both schemes,the changes of water levels are less than 5cm.The velocities reduce inside the array,and both upstream and downstream of the array,but increase along the sides of the array and in the neighboring channels.The impacts of mean tidal current power density are distributed inside and around the arrays,especially tending to the direction of the preferential flow.
Based on a well-verified 2Dmathematical model for tidal current,the tidal current fields with two different power extraction schemes are simulated,where the presence of tidal current turbines is included as an additional bed friction source term.Guishan Channel,which is in a sea with many islands,is taken as a typical area where tidal current energy is extracted.The changes of water level,current velocity and mean tidal current power density are analyzed to study the far-field hydro-dynamic impact of tidal current energy extraction.The simulated results illustrate that the first scheme with a power coefficient 0.3is found to have lower impact on original flow than the second scheme(the power coefficient equals 0.5).In both schemes,the changes of water levels are less than 5cm.The velocities reduce inside the array,and both upstream and downstream of the array,but increase along the sides of the array and in the neighboring channels.The impacts of mean tidal current power density are distributed inside and around the arrays,especially tending to the direction of the preferential flow.
引文
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[13]GARRETT C,CUMMINS P.The efficiency of a turbine in a tidal channel[J].J Fluid Mech,2007,588:243-251.
[14]MACLEOD A J,BARNES S,RADOS K G,et al.Wake effects in tidal current turbine farms[C]//Proceedings of the MAREC Conference.Newcastle:IMAREST,2002:49-53.
[15]BRYDEN I G,COUCH S J.How much energy can be extracted from moving water with a free surface:aquestion of importance in the field of tidal current energy[J].Renewable Energy,2007,32(11):1961-1966.
[16]DEFNE Z,HAAS K A,FRITZ H M.Numerical modeling of tidal currents and the effects of power extraction on estuarine hydrodynamics along the Georgia coast,USA[J].Renewable Energy,2011,36:3461-3471.
[17]AHMADIAN R,FALCONER R,BOCKELMANNEVANS B.Far-field modeling of the hydro-environmental impact of tidal stream turbines[J].Renewable Energy,2012,38:107-116.
[18]NEILL S,JORDAN J,COUCH S J.Impact of tidal energy converter(TEC)arrays on the dynamics of headland sand banks[J].Renewable Energy,2012,37:387-397.
[19]LIU Hongwei,MA Shun,LI Wei.A review on the development of tidal current energy in China[J].Renewable and Sustainable Energy Reviews,2011,15:1141-1146.
[20]COUCH S J,BRYDEN I.Tidal current energy extraction:hydrodynamic resource characteristics[J].Proceedings of the Institution of Mechanical Engineers,Part M:Journal of Engineering for the Maritime Environment,2006,220:185-194.
[21]BLUNDEN L S,BAHAJ A S.Tidal energy resource assessment for tidal stream generators[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2007,221:137-146.
[2]MYERS L E,BAHAJ A S.An experimental investigation simulating flow effects in first generation marine current energy converter arrays[J].Renewable Energy,2012,37:28-36.
[3]ROURKE F O,BOYLE F,REYNOLDS A.Tidal energy update 2009[J].Applied Energy,2010,87:398-409.
[4]Hammerfest Sitrom A S.Norwegian Technology for Tidal Energy to be Further Developed in Great Britain[R/OL].[2008].http://www.hammerfeststrom.com/.
[5]Verdant Power Ltd.Verdant Power's Free Flow Turbines[R/OL].[2008].http://verdantpower.com/what-systemsint/.
[6]BAI Luolin,SPENCE R,DUDZIAK G.Investigation of the influence of array arrangement and spacing on tidal energy converter(TEC)performance using a 3-dimensional CFD model[C]//Proceedings of the 8th European Wave and Tidal Energy Conference.Uppsala:EWTEC,2009:654-660.
[7]MYERS L E,BAHAJ A S.Power output performance chararcteristics of a horizontal axis marine current turbine[J].Renewable Energy,2006,31:197-208.
[8]STEPHEN R T,ALEXANDER B P,JOE B,et al.Modelling tidal current turbine wakes using a coupled RANS-BEMT approach as a tool for analysing power capture of arrays of turbines[J].Ocean Engineering,2011,38:1300-1307.
[9]BATTEN W M J,BAHAJ A S,MOLLAND A F,et al.Experimentally validated numerical method for the hydrodynamic design of horizontal axis tidal turbines[J].Ocean Engineering,2007,34:1013-1020.
[10]BRYDEN I G,COUCH S J.ME1-marine energy extraction:tidal resource analysis[J].Renewable Energy,2006,31:133-139.
[11]COUCH S J,BRYDEN I G.Large-scale physical response of the tidal system to energy extraction and its significance for informing environmental and ecological impact assessment[C]//Proceedings of Oceans 2007-Europe International Conference.Scotland:IEEE,2007:912-916.
[12]HANSEN M O L.Aerodynamics of Wind Turbines[M].2nd ed.London:EARTHSCAN,2008:28-35.
[13]GARRETT C,CUMMINS P.The efficiency of a turbine in a tidal channel[J].J Fluid Mech,2007,588:243-251.
[14]MACLEOD A J,BARNES S,RADOS K G,et al.Wake effects in tidal current turbine farms[C]//Proceedings of the MAREC Conference.Newcastle:IMAREST,2002:49-53.
[15]BRYDEN I G,COUCH S J.How much energy can be extracted from moving water with a free surface:aquestion of importance in the field of tidal current energy[J].Renewable Energy,2007,32(11):1961-1966.
[16]DEFNE Z,HAAS K A,FRITZ H M.Numerical modeling of tidal currents and the effects of power extraction on estuarine hydrodynamics along the Georgia coast,USA[J].Renewable Energy,2011,36:3461-3471.
[17]AHMADIAN R,FALCONER R,BOCKELMANNEVANS B.Far-field modeling of the hydro-environmental impact of tidal stream turbines[J].Renewable Energy,2012,38:107-116.
[18]NEILL S,JORDAN J,COUCH S J.Impact of tidal energy converter(TEC)arrays on the dynamics of headland sand banks[J].Renewable Energy,2012,37:387-397.
[19]LIU Hongwei,MA Shun,LI Wei.A review on the development of tidal current energy in China[J].Renewable and Sustainable Energy Reviews,2011,15:1141-1146.
[20]COUCH S J,BRYDEN I.Tidal current energy extraction:hydrodynamic resource characteristics[J].Proceedings of the Institution of Mechanical Engineers,Part M:Journal of Engineering for the Maritime Environment,2006,220:185-194.
[21]BLUNDEN L S,BAHAJ A S.Tidal energy resource assessment for tidal stream generators[J].Proceedings of the Institution of Mechanical Engineers,Part A:Journal of Power and Energy,2007,221:137-146.