主流乱れの長さスケールが境界層内撹乱の成長に及ぼす影響(境界層・せん断流・遷移(1),一般講演)

概要

論文の詳細を見る
The purpose of this study is clarify the boundary layer transition process influenced by free stream turbulence. This report focuses on effect of the length scale and the intensity of free stream turbulence. The free stream turbulence generated by a turbulence grid mounted upstream of the contraction has longer scale in the streamwise direction than that in the case that a grid mounted downstream of the construction. The flow visualization and hot-wire measurement results show that generation of the wave packet that has the normalized streamwise wave number which is correspond with that of the Tollmien-Schlichting wave predicted by the linear stability theory. This wave packet immediate forms A shape and breaks down to a turbulent spot. It is concluded that the scenario of the transition due to the large scale and low level free stream turbulence is essentially different from the scenario in which the non-modal growth plays an important role in the case of the moderate level free stream turbulence.
日本流体力学会の論文
2007-08-06