Experimental Control of Turbulent Boundary Layers with In-plane Travelling Waves.
Experimental Control of Turbulent Boundary Layers with In-plane Travelling Waves.
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DOI：
10.1007/s10494-018-9926-2
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Morrison JF
中科院分区：
文献类型：
--
作者：
Bird J;Santer M;Morrison JF
本文概述了利用一种新的活动表面产生的沿流行波的跨向壁速度对湍流边界层的实验控制。创新的表面包括一个基于kagome晶格几何的气动驱动的柔性结构，支持预拉伸的膜皮肤。结构的精心设计使可变长度和速度的波能够在平面上以稳健和可重复的方式产生，其频率和振幅已知对边界层有有利的影响。两个表面被开发出来，一个初步模块在顺流方向延伸152毫米，另一个较长模块在顺流方向延伸2.9米，以便边界层能够适应强迫施加的新表面条件。当驱动较短的1.5 m部分表面时，产生上游行波，在Reτ = 1125的边界层中记录到阻力减少21.5%。在相同的流动条件下，向下游移动产生的阻力减少幅度要小得多，为2.6%，与当前模拟中观察到的趋势一致。通过恒温热线测量粘性亚层的平均速度梯度来确定阻力减少，同时激光多普勒振动仪测量表面记录壁面运动。尽管动态表面的力学会导致一些面外运动（与面内流动运动相比，这是很小的），但积极的减阻结果对于未来在更高雷诺数下的研究是令人鼓舞的。
The experimental control of turbulent boundary layers using streamwise travelling waves of spanwise wall velocity, produced using a novel active surface, is outlined in this paper. The innovative surface comprises a pneumatically actuated compliant structure based on the kagome lattice geometry, supporting a pre-tensioned membrane skin. Careful design of the structure enables waves of variable length and speed to be produced in the flat surface in a robust and repeatable way, at frequencies and amplitudes known to have a favourable influence on the boundary layer. Two surfaces were developed, a preliminary module extending 152 mm in the streamwise direction, and a longer one with a fetch of 2.9 m so that the boundary layer can adjust to the new surface condition imposed by the forcing. With a shorter, 1.5 m portion of the surface actuated, generating an upstream-travelling wave, a drag reduction of 21.5% was recorded in the boundary layer with Reτ = 1125. At the same flow conditions, a downstream-travelling produced a much smaller drag reduction of 2.6%, agreeing with the observed trends in current simulations. The drag reduction was determined with constant temperature hot-wire measurements of the mean velocity gradient in the viscous sublayer, while simultaneous laser Doppler vibrometer measurements of the surface recorded the wall motion. Despite the mechanics of the dynamic surface resulting in some out-of-plane motion (which is small in comparison to the in-plane streamwise movement), the positive drag reduction results are encouraging for future investigations at higher Reynolds numbers.
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影响因子：
2.4
作者：
Gouder, Kevin;Potter, Mark;Morrison, Jonathan F.
通讯作者：
Morrison, Jonathan F.
影响因子：
3.7
作者：
Park, Hyungmin;Sun, Guangyi;Kim, Chang-Jin CJ
通讯作者：
Kim, Chang-Jin CJ
DOI：
10.1016/j.ijsolstr.2016.11.006
发表时间：
2017-02-01
影响因子：
3.6
作者：
Bird, James;Santer, Matthew;Morrison, Jonathan
通讯作者：
Morrison, Jonathan
影响因子：
4.6
作者：
LAADHARI, F;SKANDAJI, L;MOREL, R
通讯作者：
MOREL, R
DOI：
10.1063/1.858653
发表时间：
1993-03-01
期刊：
PHYSICS OF FLUIDS A-FLUID DYNAMICS
影响因子：
--
作者：
KIM, J;HUSSAIN, F
通讯作者：
HUSSAIN, F