随机风场空间相干性研究

Research on Spatial Coherence of Stochastic Wind Field

摘要:

提出了一种描述随机风场空间相干特性的相位差谱模型,可用于大范围随机风场模拟.经典理论中一般采用相干函数来描述空间风场相干特性.研究发现,相干函数只是二阶数值特征,远不能描述两点脉动风速相干特性的丰富概率信息.研究表明,Fourier相位差谱可以对脉动风速时程的相干特性进行全面的描述.基于对影响相位差主要因素的分析,提出了相位差谱的基本模型.通过与实测相位差谱的比较,验证了所提模型的合理性与适用性.应用该模型进行了风场模拟,效果良好.

Abstract:

This paper presents a phase-delay spectrum model to describe the spatial coherence of stochastic wind field,which can be used in large-scale stochastic wind field simulation.Coherence function is usually adopted to describe the spatial coherence in classic theory.It is found that coherence function is only second-order numerical characteristics and is far from describing the abundant probabilistic information of coherence of fluctuating wind speed.This study shows that Fourier phase-delay spectrum can give a comprehensive description of the coherence of fluctuating wind speed.Based on the analysis of primary factors affecting phase-delay,a basic model of phase-delay spectrum is presented.By a comparison with the measured phase-delay spectrum,the rationality and applicability of the model are verified.Finally,wind field simulation with this model obtains a good effect.