Experiments on the behaviour of an axisymmetric turbulent boundary layer with a sudden circumferential strain
Experiments on the behaviour of an axisymmetric turbulent boundary layer with a sudden circumferential strain
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突发周向应变轴对称湍流边界层行为实验
DOI：
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发表时间：
1974
影响因子：
3.7
通讯作者：
G. Mellor
中科院分区：
文献类型：
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作者：
L. Bissonnette;G. Mellor
对轴向旋转圆柱上的三维湍流边界层进行了平均速度场和平均湍流场的测量。圆柱体模型由两部分组成：静止部分和旋转的后体。采用热线风速测量技术，获得了倾斜流动中完整的平均速度和湍流测量结果。首先讨论了三维边界层的一般行为：观察到了两个类似于二维壁面和缺陷层的渐近层；它们被证明是从平均运动方程演化而来的。根据这些结果，对标量涡粘性假设进行了探讨。利用传统的长度尺度假设和雷诺应力张量方程，建立了壁区定律中曲率效应的预测；在这种情况下，结果是壁区定律的半对数部分的斜率较小，这种分析不需要在平面、二维流动所必需的假设之外的假设。模型的几何形状是这样的，平均应变速率沿流线发生快速变化。从能量耗散、扩散和再分配过程中能量耗散、扩散和再分配过程的历史可以得出一些基本的结论。
Mean velocity and mean turbulent field measurements are performed for the case of a three-dimensional turbulent boundary layer on an axially rotated cylinder. The cylinder model consists of two parts: a stationary section followed by a spinning afterbody. Techniques of hot-wire anemometry are employed, which yield complete mean velocity and turbulence measurements in skewed flows. The general behaviour of the three-dimensional boundary layer is first discussed: two asymptotic layers analogous to the two-dimensional wall and defect layers are observed; they are shown to evolve from the equations of mean motion. The hypothesis of scalar eddy viscosity is investigated in the light of these results. Using conventional length scale assumptions together with the Reynolds stress tensor equations, a prediction of curvature effects in the law of the wall region is developed; a result in the present case is a smaller slope of the semi-logarithmic portion of the law of the wall, No assumptions over and above those necessary for plane, two-dimensional flow are required for this analysis. The geometry of the model is such that a rapid change in mean rate of strain occurs along the streamlines. From the history of the components of the $\overline{u_iu_j}$ tensor, it is possible to draw some fundamental conclusions concerning the dynamics of the energy dissipation, diffusion and redistribution processes.