自适应时频插值非平稳实测风速模拟  

Simulation of Non-stationary Measured Wind Velocities Based on Adaptive Time-Frequency Interpolation

作　　者：李春祥[1] 罗锞兴 韩慧 曹黎媛 LI Chunxiang;LUO Kexing;HAN Hui;CAO Liyuan(School of Mechanics and Engineering Science,Shanghai University Shanghai,200444,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444

出　　处：《振动．测试与诊断》2023年第3期539-546,622,共9页Journal of Vibration,Measurement & Diagnosis

基　　金：国家青年科学基金资助项目(52108460)。

摘　　要：经典的基于理论规范谱的谱表示法(spectral representation method,简称SRM)可有效模拟自然界大部分风速,但在应用于极端恶劣的实测风速模拟时存在较大偏差,且模拟效率低下。针对这一问题,分别以台风“杜鹃”(弱非平稳)和实测下击暴流风速(强非平稳)为研究背景,首先,以实测风速谱为目标,对理论规范谱进行修正,建立基于修正谱的模拟方案,使得模拟风速更加贴近真实的实测风速;其次,在基于修正谱的风速模拟平台中,引入时频插值技术,并以“平均分辨率”为量化指标,设计一种自适应插值增强方案,从二维角度,实现时频域插值点非均匀分布的自动化确定,避免时域、频域上的局部精度损失和人工测试插值参数的麻烦。数值表明:基于上述方案的模拟结果较好地保留了非平稳实测风速的时域特性和功率谱特性;自适应时频插值方案的引入,在误差损失减小78%左右的情况下,模拟效率提高了76%左右。The classical spectral representation method(SRM)based on theoretical spectrum can effectively simulate most wind velocities in nature.However,it has great deviation and low simulation efficiency as ap-plied to the simulation of extreme non-stationary measured wind velocity.To solve this problem,this paper takes typhoon"Dujuan"(weak non-stationary)and measured downburst(strong non-stationary)as the research background.Taking the measured wind velocity spectrum as the target,the theoretical spectrum is modified,and the simulation scheme based on the modified spectrum is established to make the simulated wind velocity more close to the measured wind velocity.Time-frequency interpolation technology is introduced into the simu-lation of wind velocity based on modified spectrum.And an adaptive interpolation-enhanced scheme is devised,which uses"average resolution"as the quantization index.The automatic determination of non-uniform distribu-tion of interpolation points in time and frequency domain is realized,which avoids the local precision loss in time and frequency domain and the trouble of testing interpolation parameters manually.The final simulation re-sults are very close to the measured wind velocities,the time-domain characteristics and power spectrum char-acteristics of the non-stationary measured wind velocity are well retained.Moreover,the introduction of interpo-lation technology,the simulation efficiency is improved by about 78%,when the error loss is reduced by about 76%.

关 键 词：实测下击暴流 谱表示法 目标谱修正 时-频插值 自适应方案 非均匀分布 

分 类 号：O324[理学—一般力学与力学基础] TU311.4[理学—力学]