The use of a contraction to improve the isotropy of grid-generated turbulence

作者：Geneviève Comte-Bellot, S. Corrsin · 发表于：Journal of Fluid Mechanics · 年份：1966 · DOI：10.1017/s0022112066000338 · 被引用次数：929 · 研究领域：Fluid Dynamics and Turbulent Flows、Plant Water Relations and Carbon Dynamics、Solar and Space Plasma Dynamics

It is found that when the average kinetic energies of normal velocity components in decaying, grid-generated turbulence are equilibrated by a symmetric contraction of the wind tunnel, this equality can persist downstream. A second result is further confirmation of the fact that the best power-law fit to the inverse turbulent energy during the early part of decay is near ( x–x 1 ) 1·25 , for both rod grids and disk grids. The Kolmogorov decay law $\sim (t - t_1)^{\frac{10}{7}}$ is re-derived by a spectral method which is essentially equivalent to the original. Finally, a crude theoretical estimate of component energies in the straight duct after a weak contraction seems to support the experiments.