Abstract To investigate the effects of turbulence integral scale, four rectangular models were tested in grid-generated turbulent flows, and the characteristics of fluctuating pressures on windward surfaces were obtained. The results show that all statistical parameters except the mean pressures depend on both the longitudinal integral scale ( L u x ) and depth (D) of the model. The root-mean-square (rms) values of the fluctuating pressure coefficients and their correlation as well as the spanwise coherence increase with the turbulence integral scale. As the integral scale decreases, the power spectra of the fluctuating pressures in the low-frequency region, which are controlled by the quasi-steady effect, remain almost unchanged, whereas those in the high-frequency region attenuate more rapidly. To seek a potential modification method for correcting the error margin caused by an imprecisely simulated turbulence integral scale, an empirical model of aerodynamic admittance function (AAF) of fluctuating pressure was proposed with consideration of L u x /D as a key variable. Finally, using the fluctuating pressure on the model with a side ratio of 1:3 as an example, the error margins of the fluctuating pressures were discussed. It was discovered that the maximum deviation of the rms value of the fluctuating pressure coefficient reached approximately 25% when the simulated turbulence integral scale was one-sixth the target value.

中文翻译：

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湍流积分尺度对风压脉动特性的影响

摘要 为研究湍流积分尺度的影响，在网格产生的湍流中测试了四种矩形模型，获得了迎风面压力脉动特征。结果表明，除平均压力外的所有统计参数都取决于模型的纵向积分尺度 (Lux) 和深度 (D)。脉动压力系数的均方根 (rms) 值及其相关性以及展向相干性随着湍流积分尺度的增加而增加。随着积分尺度的减小，受准稳态效应控制的低频区脉动压力的功率谱几乎保持不变，而高频区的脉动压力功率谱衰减得更快。为了寻找一种潜在的修正方法来修正由不精确模拟的湍流积分尺度引起的误差范围，提出了一种以Lux/D为关键变量的脉动压力气动导纳函数（AAF）经验模型。最后，以边比为1:3的模型上的脉动压力为例，讨论了脉动压力的误差范围。发现当模拟湍流积分尺度为目标值的六分之一时，脉动压力系数的均方根值的最大偏差达到约25%。以L ux /D为关键变量，提出了脉动压力气动导纳函数(AAF)的经验模型。最后，以边比为1:3的模型上的脉动压力为例，讨论了脉动压力的误差范围。发现当模拟湍流积分尺度为目标值的六分之一时，脉动压力系数的均方根值的最大偏差达到约25%。以L ux /D为关键变量，提出了脉动压力气动导纳函数(AAF)的经验模型。最后，以边比为1:3的模型上的脉动压力为例，讨论了脉动压力的误差范围。发现当模拟湍流积分尺度为目标值的六分之一时，脉动压力系数的均方根值的最大偏差达到约25%。