论文标题
QSQH比例相互作用理论在近壁湍流中的扩展到所有速度成分
Extension of QSQH theory of scale interaction in near-wall turbulence to all velocity components
论文作者
论文摘要
QSQH理论扩展到所有三个速度成分，这些速度成分考虑了壁摩擦大规模成分的方向的波动。发现这种效果很重要。它解释了与平均速度，雷诺压力以及壁正常速度波动相比，纵向和跨度速度波动对雷诺数变化的敏感性。分析表明，纵向速度波动随雷诺数的变化的变化主要取决于振幅和壁法尺度调制的变化，而振幅和壁法尺度调制了宇宙平均速度曲线的差异，外部，大型，雷诺数依赖于雷诺依赖的运动。跨度速度波动的变化主要取决于壁摩擦大规模分量的方向的波动。其他第二矩的雷诺数依赖性并非由这些机制主导，因为平均壁正常速度和平均跨度速度为零。在任何两个高雷诺克近壁流中，第二个速度的差异之间的差异之间的显式关系均得出。对比较给出了壁平行速度成分的根平方的令人满意的一致性，该速度成分距壁的距离范围内，该距离距离壁的距离范围内，大规模动作的调制占主导地位。对数定律常数的差异，平均速度曲线的形状以及由大规模运动的差异引起的第二次速度矩的差异，并定量地得出了估计。
The QSQH theory is extended to all three velocity components taking into account the fluctuations of the direction of the large-scale component of the wall friction. This effect is found to be significant. It explains the large sensitivity of the fluctuations of longitudinal and spanwise velocities to variations in the Reynolds number in comparison with the sensitivity of the mean velocity, the Reynolds stress, and the wall-normal velocity fluctuations. The analysis shows that the variation of the longitudinal velocity fluctuations with the Reynolds number is dominated by the variation of the amplitude and wall-normal-scale modulation of the universal mean velocity profile by the outer, large-scale, Reynolds-number-dependent motions. The variation of spanwise velocity fluctuations is dominated by the fluctuations of the direction of the large-scale component of the wall friction. The Reynolds number dependence of the other second moments is not dominated by these mechanisms because the mean wall-normal velocity and the mean spanwise velocity are zero. Explicit relationships between the differences in the second moments of velocity in any two high-Reynolds-number near-wall flows were derived. The comparisons gave a satisfactory agreement for the root-mean square of the wall-parallel velocity components in the range of the distances from the wall where modulation by large-scale motions dominates. Relationships between the differences of the constants of the logarithmic law, the shape of the mean velocity profile, and the differences of the second moments of velocity caused by the differences in large-scale motions were derived and estimated quantitatively.
