下击暴流非平稳脉动风速数值模拟

发布时间：2018-03-21 21:47

本文选题：下击暴流　切入点：非平稳　出处：《振动与冲击》2014年14期 　论文类型：期刊论文

【摘要】：针对大气边界层近地风不同、下击暴流平均风速具有明显时变性及脉动风速具有较强非平稳特征,通过Kaimal非均匀调制函数的建立方法,获得Davenport调制函数、Simiu调制函数、Harris调制函数,为有效实现非平稳脉动风速模拟提供首要条件;考虑自回归AR模型时变性,建立非平稳随机过程TAR时变模型,为实现非平稳脉动风速模拟提供有效方法;考虑下击暴流平均风速时变特征,对下击暴流非平稳脉动风速进行模拟。结果表明,模拟的下击暴流非平稳脉动风速相关性随不同位置间距增大而减弱,振幅随时变平均风速增大而增大,与实际风场特性吻合,表明非均匀调制函数有效;功率谱时变特征明显,与目标时变谱时变特征吻合,且样本统计平均功率谱、相关函数与目标均吻合,表明下击暴流非平稳脉动风速模拟方法有效。
[Abstract]:In view of the difference of near-ground wind in the atmospheric boundary layer, the average wind speed of the downburst is obviously time-varying and the fluctuating wind speed has strong non-stationary characteristics. The Kaimal modulation function is obtained by establishing the non-uniform modulation function of Davenport. In order to effectively realize the simulation of non-stationary pulsating wind speed, the TAR time-varying model of non-stationary stochastic process is established considering the time-varying of autoregressive AR model, which provides an effective method for the simulation of non-stationary pulsating wind speed. Considering the time-varying characteristics of the average wind speed of the downburst flow, the non-stationary pulsating wind speed of the downburst flow is simulated. The results show that the correlation of the simulated non-stationary pulsating wind speed of the downburst flow decreases with the increase of the distance between different locations. The amplitude increases with the increase of the mean wind speed, which is consistent with the actual wind field, which shows that the non-uniform modulation function is effective, the time-varying characteristic of the power spectrum is obvious, the time-varying characteristic of the time-varying spectrum is consistent with the time-varying characteristic of the target, and the average power spectrum of the sample is statistically significant. The correlation function coincides with the target, which indicates that the simulation method of non-stationary pulsating wind speed is effective.
【作者单位】：华东交通大学土木建筑学院;
【基金】：国家自然科学基金项目(11162005) 江西省自然科学基金项目(20132BAB216003) 江西省教育厅基金项目(GJJ13310)
【分类号】：TU119.21

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