NEAR-WALL STRUCTURE OF A TURBULENT BOUNDARY-LAYER WITH RIBLETS
NEAR-WALL STRUCTURE OF A TURBULENT BOUNDARY-LAYER WITH RIBLETS
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DOI：
10.1017/s0022112089002892
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发表时间：
1989-11-01
影响因子：
3.7
通讯作者：
CHOI, KS
中科院分区：
文献类型：
--
作者：
CHOI, KS
在零压力梯度条件下，对光滑壁面和波纹壁面上的近壁湍流结构进行了详细的风洞研究。使用热线/薄膜风速法获得了时间平均量以及有条件采样剖面，同时使用烟雾线技术和激光片进行了流动可视化。实验结果表明，波纹表面附近的湍流边界层结构发生了明显的变化。这种变化被限制在靠近壁面的小体积内。在对流动可视化进行广泛研究的基础上，提出了爆发序列的概念模型，并得到了条件采样速度场结果的支持。讨论了波纹管减少湍流阻力的可能机理。
A detailed wind tunnel study has been carried out on the near-wall turbulence structure over smooth and riblet wall surfaces under zero pressure gradient. Time-average quantities as ‘well as conditionally sampled profiles were obtained using hotwire/film anemometry, along with a simultaneous flow visualization using the smoke-wire technique and a sheet of laser light. The experimental results indicated a significant change of the structure in the turbulent boundary layer near the riblet surface. The change was confined within a small volume of the flow close to the wall surface. A conceptual model for the sequence of the bursts was then proposed based on an extensive study of the flow visualization, and was supported by the results of conditionally sampled velocity fields. A possible mechanism of turbulent drag reduction by riblets is discussed.