大涡模拟中入流边界条件脉动风速的处理对计算流体动力学的数值模拟结果的正确性和精度有着至关重要的影响,文章对在运用DSRFG法生成湍流脉动风的算法中,研究了几个相关参数(包括脉动风速能量谱离散化的区间样本数Kmax,能量谱密度模拟所选取三角级数向量组的个数N,空间尺度参数因子θ1和时间尺度参数因子θ2)的数值选取,对入流脉动风速功率谱和脉动风速竖向空间相关性模拟结果的影响.模拟计算结果表明:相对于其他3个参数,空间尺度参数因子θ1的选取相对比较离散.结合DSRFG算法和文章提出的最佳参数取值,模拟得到与实际大气风场特性吻合较好的冯卡门谱及其竖向相关特征.
The modeling of the inlet fluctuated wind velocity in large eddy simulation plays an important effect on the precision of computational fluid dynamics numerical simulation of wind loads on buildings .Along with the application of DSRFG method in turbulence wind velocity , the study on selecting the reasonable numerical val-ues of some main parameters in this method was conducted in this paper .These key parameters mainly include:the discretized sampling number for the simulated energy spectrum of fluctuated wind speed , the number of tri-angular function series in modeling the energy spectrum , the spatial and time scale parameter .The effect of these parameters on the simulated power spectrum and vertical spatial correlation of fluctuated wind speed were studied by an example of inlet fluctuated wind velocity simulation for the CFD application .Simulated results showed that the more scattered numerical values in spatial scale parameter were found to fit the empirical vertical spatial correlation of fluctuated wind speed .Finally a numerical simulation of inlet fluctuated wind velocity was conducted in this study through DSRFG method with the proposed values for these four parameters , and the sim-ulated results could represent the von-Karman spectrum and its vertical spatial correlation with considerable pre-cision.