摘要
为提高波能俘获效率,提出了一种由固定平台、垂直轴对称浮体、管状结构和三个动力输出(PTO)机构组成的多自由度波能转换装置,其中管状结构与固定平台之间采用万向接头连接,浮体与管状结构间采用运动导向机构连接使两者具有相同的纵摇和横摇运动,浮体沿管状结构滑动的能量俘获采用机械整流PTO系统使与之连接的发电机实现单向旋转,其余两个PTO安装在铰接轴处;利用势流理论建立了该装置水动力分析的时域计算模型,其中静水力和Froude-Krylov力采用沿浮体静浮时湿表面积分的线性和沿瞬时湿表面积分的非线性两种方法分别计算;为考虑可能出现的大幅纵/横摇运动的影响,垂向机械整流PTO负载力分解到纵荡、横荡和垂荡方向时不作线性化处理;分析了随浪规则波作用下,波高、垂向PTO和纵摇PTO阻尼系数的影响。结果表明:在相同参数下采用非线性方法所得垂向PTO的波能浮获效率及装置总效率均小于线性方法所得结果,而纵摇PTO的波能浮获效率则大于线性方法结果;波高越大,两种方法所得结果之间的差值越大。
In order to improve the wave energy conversion efficiency,a multi-degree-of-freedom wave energy converter composed of a fixed platform,a vertical axisymmetric buoy,a tubular structure and three power take-off(PTO)mechanisms was proposed.The tubular structure was connected with the fixed platform by a universal joint,and the buoy and tubular structure were connected by a motion guiding mechanism to ensure that the two bodies have same pitch and roll motions.The mechanical motion rectifier PTO system was used to absorb the energy of the buoy sliding along the tubular structure to realize the unidirectional rotation of the generator while the other two PTOs were installed at the articulated shaft.A time domain hydrodynamic analysis approach was established by using potential theory,in which the hydrostatic forces and Froude-Krylov forces were calculated by the linear method integrated to the wetted surface of the buoy's hydrostatic equilibrium position and the nonlinear method integrated to the wetted surface of the buoy at an instant in time.In order to consider the possible influence of large angle pitch or roll motions,the vertical mechanical motion rectifier PTO force was not linearized when decomposed into surge,sway and heave motion directions.The effects of wave height,vertical PTO and pitch PTO damping coefficients under following regular waves were analyzed.It is shown that under the same parameters,the wave energy conversion efficiency of vertical PTO and the total efficiency of the converter calculated by nonlinear method are lower than those obtained by linear method,while the efficiency of pitch PTO is greater than that of linear method,and that the higher the wave height is,the greater the difference between the results obtained by two methods is.
作者
王冬姣
WANG Dong-jiao(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,China)
出处
《船舶力学》
EI
CSCD
北大核心
2023年第5期646-658,共13页
Journal of Ship Mechanics
基金
国家重点研发计划资助项目(2018YFB1501904)
关键词
多自由度
波能转换装置
机械整流
multiple degrees of freedom
wave energy converter
mechanical motion rectifier
