| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2011: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2010: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2009: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
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| Research Abstract |
The effect of the spanwise three-dimensionality of the rough wall introduced by longitudinal micro-grooves has been investigated on the mean and turbulent quantities for a turbulent boundary layer. The boundary layer development has little effect of the three-dimensionality. For the outer layer, the streamwise mean velocity and turbulent intensity profiles are well agreement with those of the two-dimensional rough wall flow, but near the rough wall these values increase. From the detailed measurement near the rough wall, the streamwise mean velocity and turbulent intensity profiles show a periodicity in the spanwise direction corresponding to the micro-grooves. Behind the micro-groove, the streamwise mean velocity is accelerated and the turbulent intensity is enhanced in comparison with those of the two-dimensional rough wall flow. On the drag acting on the rough wall, the three-dimensionality has little influence. The virtual origin of the height direction estimated by the pressure distribution around a roughness element and the drag shifts downward compared with that of the two-dimensional rough wall flow.
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