基于小波方法的随机脉动风模拟

根据小波的多分辨率分析性质,利用小波重构算法,采用正交小波基对脉动风速进行模拟.选取适当的小波基,假定最粗糙尺度上的尺度系数(即原始信号在最粗糙尺度上的近似),基于线性估计原理,由其线性组合估计同一尺度上的小波系数(即原始信号在该尺度上的细节内容),利用逆小波变换反复迭代计算,就可以得到原始信号在最精确尺度上的近似.根据这一思路,模拟了与Kaimal谱一致的苏通桥某点的纵向脉动风速,验证了小波方法模拟随机风场的有效性.

Simulation of Random Fluctuating Wind Speed Based on Wavelet Method

According to the multiresolution analysis property and the reconstruction algorithm of wavelet,the time history of fluctuating wind speed is simulated by using orthogonal wavelet bases.After the appropriate wavelet bases are selected,the scale coefficient at the coarsest scale,namely the approximations of the original signal are supposed and the wavelet coefficient at the same scale,namely the details of it are estimated by a linear combination of the components of the scale coefficient based on the linear estimation principle.The approximations of the original signal at the finest scale are generated by iteratively using the inverse wavelet transform.Some artificial time history of fluctuating wind speed on the site of Sutong Bridge are generated following this train of thought,which are submitted to Kaimal spectrum.The efficiency of the simulation of the stochastic wind fluctuation data is proved by using the wavelet bases.