摘要：非平稳脉动风速的数值模拟关键因素是要获得时变功率谱。根据进化谱理论，时变功率谱可以通过某个确定性调制函数对现有平稳功率谱(例如kaimal谱、Davenport谱或Simiu谱)进行调制而获得。但是，目前并没有值得认可的功率谱调制函数，以至于非平稳脉动风速的模拟很少被关注。为了获得合理的调制函数来实现非平稳脉动风速的模拟，首先，将某一段时间 内的非平稳脉动风速离散成 段足够短时间 内可以近似为平稳脉动风速的时间序列；其次，当 时，通过组合 段平稳脉动风速的功率谱来获得时变功率谱；最后，通过将获得的时变功率谱等于进化谱而推导出相应的调制函数，并运用谐波合成法模拟了三个空间点的非平稳脉动风速。
Abstract: For the numerical simulation of non-stationary fluctuating wind velocity, the critical factor is to obtain time-varying power spectra (referred here to as the TVPS). According to the theory of evolutionary power spectra (referred to as the EPS), TVPS, namely EPS, can be acquired through this way using a deterministic modulating function (referred to as the DMF) to modulate a known power spectra of stationary fluctuating wind velocity such as Kaimal spectra, Davenport spectra or Simiu spectra. But there is not a DMF that can be universally acknowledged currently, so that the simulation of non-stationary fluctuating wind velocity can be scarcely paid attention to. In order to acquire a DMF to stimulate the non-stationary fluctuating wind velocity, firstly this paper assumes that a non-stationary fluctuating wind velocity during the time is made of segments of stationary fluctuating wind velocity with a very short time ; then, TVPS can be obtained by connecting each power spectra from segments of stationary fluctuating wind velocity when ; finally, DMF has been deduced through the relation that TVPS is equal to EPS, and the simulations of the non-stationary wind velocity for three spatial points has been carried out using harmony superposition method.
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