4113 軸流中の回転円筒上乱流境界層の実験 : 外層の整構造(G05-9 回転に伴う流れ,G05 流体工学)  [in Japanese] 4113 Experiments on the Turbulent Boundary Layer on a Cylinder Rotating in an Axial Flow : Coherent Structure in the Outer Layer  [in Japanese]

This study is concerned with the turbulent structure of a three-dimensional boundary layer on a thin cylinder rotating in a uniform stream at the velocity ratio Ω_m=0, 0.5 and 1. Measurements were made for a single hot-wire probe at R_θ of about 2500. Mean profiles of the axial and peripheral velocity components were examined in inner scaling and outer scaling, and then the statistical properties of the axial fluctuation were represented by the intermittency factor and power spectrum. It is shown that an energy bump appears in the lower frequency range of spectra in the rotating cases.