论文标题
在可压缩流体动力湍流中的动能级联
On cascade of kinetic energy in compressible hydrodynamic turbulence
论文作者
论文摘要
使用中等雷诺数的三维流体动力衰减湍流和初始马赫数$ m = 1 $的直接数值模拟,研究了动能的湍流级联的性质。比较了Karman-Howarth-MONIN(KHM)和低通滤波/粗粒剂方法的可压缩版和不可压缩版。在模拟中,总能量是充分保守的。量表依赖性的KHM和粗粒元的能量方程也得到了充分的保守。这两种方法显示出相似的结果,该系统对于级联的动能没有惯性范围,该级联占主导地位的区域也具有不可忽略的能量能量衰减,耗散和压力稀释效应的贡献。尽管两种方法给出了半量化的相似结果,即动能级联,耗散和压力降低速率,但它们在增量分离和滤波尺度上有所不同。这些量表不仅是相关的。这两种方法可用于找到惯性范围,并确定动能的级联/耗散率。
Properties of the turbulent cascade of kinetic energy are studied using direct numerical simulations of three-dimensional hydrodynamic decaying turbulence with a moderate Reynolds number and the initial Mach number $M=1$. Compressible and incompressible versions of the Karman-Howarth-Monin (KHM) and low-pass filtering/coarse-graining approaches are compared. In the simulation the total energy is well conserved; the scale dependent KHM and coarse-grained energy equations are also well conserved; the two approaches show similar results, the system does not have an inertial range for the cascade of kinetic energy, the region where this cascade dominates also have a non-negligible contribution of the kinetic-energy decay, dissipation, and pressure-dilatation effects. While the two approaches give semi-quantitatively similar results for the kinetic energy cascade, dissipation and pressure-dilatation rates, they differ in the increment separation and filtering scales; these scales are not simply related. The two approaches may be used to find the inertial range and to determine the cascade/dissipation rate of the kinetic energy.