リブレット面に沿う壁面噴流に関する実験的研究 : 平均・変動速度場と抵抗減少の評価

概要

論文の詳細を見る
The expectation that riblets modify the turbulent structure in the near-wall region and reduce skin-friction is experimentally examined in a wall jet. A significant difference is recognized in the mean velocity profiles and the turbulence intensities near the riblet and flat surfaces. The turbulence intensity in the streamwise direction above the riblet surface decreases by approximately 20% in comparison with that above the flat surface. The local skin-friction coefficient estimated from the mean velocity profiles in the viscous sublayer and the buffer layer indicates that the maximum reduction ratio of the drag is 11% at s^+=30〜35 within the present experimental condition ; this value of s^+ is considerably larger than that in the turbulent boundary layer.
1994-04-25