三维强迫均匀各向同性紊流直接数值模拟研究

Direct numerical simulations of 3D forced homogeneous isotropic turbulence

均匀各向同性紊流作为紊动水流的一种简化特例,被广泛应用于泥沙悬浮、污染物扩散等问题的研究中。该文利用伪谱分析方法,建立了三维均匀各向同性紊流并行计算模型,利用直接数值模拟方法生成了不同初始能量谱和不同雷诺数条件下强迫均匀各向同性紊流流场,研究了强迫均匀各向同性紊流三维紊动特性。模拟结果表明:初始能量谱取值不会影响稳定后的紊动流场;不同雷诺数条件下,雷诺数越大,强迫均匀各向同性紊流紊动强度越大,形成的惯性子区越宽。

As a simple case of turbulent flows, homogeneous isotropic turbulence is widely used in the studies of sediment transport and pollutant dispersion. A parallel numerical model of 3D homogeneous isotropic turbulence is established based on pseudo-spectral method. The turbulent flows and turbulent features of forced homogeneous isotropic turbulence with different initial energy spectra and different Reynolds number are simulated using the direct numerical simulation （DNS）. The results show that the initial energy spectra have no effects on the turbulent flow fields in the final steady state. It also can be concluded that the turbulence intensity will get higher and the inertial range will become wider with the Reynolds number increasing.