Experimental Studies on the Spectrum of Isotropic Turbulence behind Two Grids

概要

論文の詳細を見る
As a continuation of the previous work (Journ. Phys. Soc. Japan 10 (1955) 578), hot-wire measurements were made to determine the energy spectrum and decay of spectral components of turbulence behind two grids, the upstream grid having a larger mesh length than the downstream one, with a view to studying the characteristics of isotropic turbulence produced under various initial conditions and at high Reynolds numbers. Similarity of the energy spectrum holds only for high-wave-number range, while the low-wave-number characteristics of turbulence depend on the initial conditions and exhibit no similarity. On the other hand, similarity of the spectrum of vorticity is observed over almost entire wave-number region for the turbulence either behind single or double grids unless high-wave-number disturbances are superposed. Therefore, Lin's decay law, u^2^^^〜[x^<-1>+const.], is expected to be valid for the turrblence either behind a single grid or with superposed disturbances of low wave numbers. Although superposed disturbances in high wave numbers destroy similarity of the spectrum, the disturbances decay out rapidly and the similarity spectrum is stable.
社団法人日本物理学会の論文
1956-10-05