摘要
提出了特征正交分解(Proper Orthogonal Decomposition,POD)型谱表示法的各态历经风场模拟公式。将双索引频率引入到POD型谱表示法中,推导出了模拟具有各态历经性的脉动风场的计算公式,并证明了该公式模拟所得风场的前二阶统计矩是渐近无偏的和渐近各态历经的,且满足目标统计特性。引入了快速傅立叶变换(FFT)算法以提高模拟的计算效率,并给出了实用的模拟算法流程。通过比较模拟算法的计算精度,说明该算法是一种高精度算法。最后,以对龙潭河特大桥的风场模拟为算例,验证了所提算法的有效性,并分析了算法在计算效率方面的优势。
A novel method for ergodic wind field simulation is proposed by incorporating proper orthogonal decompositionbased spectral representation method and double-indexing frequencies. The spectral representation method based on proper orthogonal decomposition （POD） is described in detail firstly. By introducing the double-indexing frequencies, a new simulation algorithm is proposed to generate not only stationary but also ergodic wind fields. The first and second statistical moments of the ensemble from the simulated fields are proved to be equal to the corresponding target ones. Also, it is shown that the simulation algorithm can generate ergodic fields, that is, the temporal means and correlation functions of the simulated fields and the target fields are equal. The algorithm is computationally very efficient due to the fast Fourier transform （FFT） technique. Some extended discussion focused on the accuracy and efficiency of the algorithm is included, in comparison to the original spectral representation method. A numerical example involving simulation of turbulent wind velocity fluctuations on the Longtan river bridge is presented, by which capahilities of the proposed method are demonstrated.
出处
《振动工程学报》
EI
CSCD
北大核心
2008年第2期185-190,共6页
Journal of Vibration Engineering
基金
交通部西部交通建设科技项目(200431800024)
国家自然科学基金委创新研究群体科学基金(50621062)
国家自然科学基金重大研究计划重点项目(90715040)
科技部科技支撑计划课题(2006BAJ06B05)
关键词
风场模拟
各态历经性
谱表示法
特征正交分解(POD)
wind field simulation
ergodicity
spectral representation method
proper orthogonal decomposition （POD）
