【摘要】 使用高时间分辨率粒子图像测速技术在水槽内精细测量平板湍流边界层内不同流向、法向位置的瞬时速度矢量空间场的时间序列信号。利用实验数据对湍流各向异性的涡黏张量模式进行了实验研究,给出了湍流边界层不可压缩槽道湍流中各向异性的涡黏张量各分量的空间分布规律。各向异性的涡黏张量分量的空间分布揭示了流向平均速度的法向梯度对雷诺应力三个分量的不同贡献。涡黏张量三个分量空间上的不同规律说明对涡黏张量的各向异性的考虑是合理的,而各向同性的涡黏模型不适宜描述剪切湍流雷诺应力的物理本质。更多还原

【Abstract】 The time sequences of instantaneous velocity vector fields at different streamwise and vertical locations in a turbulent boundary layer had been measured by time-resolved particle image velocimetry(TRPIV).The research on the anisotropic eddy viscosity tensor model was carried out using the experimental dataset.The distributions in wall-normal direction for each component of anisotropic eddy viscosity tensor were presented.The results indicate the distinct contributions from the vertical gradient of the mean streamwise velocity to each component of Reynolds stress.The different distributions of each component of eddy viscosity tensor reveal that the anisotropic eddy viscosity tensor model is reasonable,and the isotropic eddy viscosity scalar model is inappropriate to describe the anisotropic nature of Reynolds stress in turbulent shear flow.更多还原