摘要
为了定量分析风速时间序列的内在波动性,采用多重分形方法研究了湍流风场的脉动特性.基于湍流风谱模型获得了不同地表面粗糙度下的湍流风速时间序列数据,利用结构函数法计算了不同风速时间序列的分形维数,分析了地表面粗糙度对风速时间序列的分形维数的影响,采用多重分形-去趋势波动分析方法对湍流风速时间序列进行多重分形分析,以探讨湍流风场的内在波动性.结果表明,随着风速时间序列的地表面粗糙度的增大,分形维数和Δα(Δα为最大与最小组成元的比值)减小,|Δg|(Δg为最大与最小组成元出现的概率的比值)增大,即风速的脉动幅度减小.
In order to quantitatively analyze the inherent volatility of wind speed data,multifractal method is used to study the turbulence characteristics of turbulent wind field.The commonly used model of turbulent wind is introduced,based on the model wind speed data of different surface roughness are obtained.The fractal dimensions of different wind speed data are calculated with structure function dimension method,and the influence of surface roughness on the fractal dimension of wind speed data is considered.The wind speed data are analyzed with multifractal detrended fluctuation analysis method to explore the intrinsic structure of turbulent wind.And the results show that the greater the surface roughness is,the smaller the fractal dimension,the smaller theΔα(Δαis the ratio of the largest to the smallest constituent elements),and the bigger the|Δg|(Δgis the ratio of the probability of occurrence of the largest and smallest constituent elements).
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2018年第11期1417-1421,共5页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金(51506123)
中国博士后基金(2015M571563)资助项目
关键词
湍流风
地表面粗糙度
分形维数
多重分形
turbulent wind
surface roughness
fractal dimension
multifractal
