POD法在定日镜风振响应计算中的应用

APPLICATION OF POD IN CALCULATION OF HELIOSTAT'S DYNAMIC RESPONSE TO WIND INDUCTION

定日镜结构风振响应中有多个振型参与,利用完全二次型组合法(CQC)可以考虑各振型间的耦合作用,得到精确结果,但计算量很大,因此提出将随机风场本征正交分解(POD)技术运用到定日镜结构响应计算中。首先给出了POD法原理,讨论了如何将POD法与CQC法结合进行结构脉动响应的频域分析;然后利用POD法分解风洞试验中多通道电子式压力扫描阀系统同步采集到的定日镜表面风压时程,分析了其本征向量的分布特点,以及各阶模态的贡献情况;最后计算出定日镜风致位移响应的均方根,并且对比采用不同阶数模态缩减得到均方根响应的误差。结果表明将POD法引入到风振响应分析中可以大大减少计算工作量并且能保证足够的精度。

There are usually several vibration modes participating in heliostat's response to wind induction.The complete quadratic combination(CQC)method can take the modes' coupling effect into account.The result is precise,however the computation work is heavy.Therefore,the proper orthogonal decomposing(POD)stochastic wind field was proposed to be applied in computation of heliostat's response to wind induction.The principle of POD was introduced,and the frequency range analysis on fluctuating response combining POD & CQC was discussed.Then POD was applied to decompose the time history of heliostat's surface wind pressure,synchronously collected by multi-channel electronic pressure scanning valve system in wind tunnel test,and the eigenvectors' distribution characteristics as well as each step's & mode's contribution were analysed.The root-mean-square of heliostat's displacement response was calculated.The response errors due to adopting mode reduction with different number of orders were compared.The result indicates that introducing POD to wind-induced response analysis can cut down much computation work while assuring adequate precision.