摘要
以"粘性"机制为理论基础,近年来在壁面湍流高分子减阻研究中提出了一种拉伸的高分子会产生自洽的等效粘度模型,这种等效粘度随离开壁面的距离而改变。通过等效粘度模型与Navier-Stokes方程的结合,运用雷诺应力模型计算壁面湍流减阻,并与基于高分子有限拉伸的非线性弹性哑铃模型的直接数值模拟结果进行比较,进一步校验了此等效粘度理论。通过肋条破坏槽道流中的边界层,显示了边界层对高分子减阻的影响,结果表明只有形成稳定的边界层,高分子才能有减阻作用。边界层是高分子减阻的首要条件,边界层中的粘性底层和对数率分布区之间的缓冲层可能是减阻的主要影响区域。
In recent studies of polymer drag reduction in wall-bounded turbulent flow based on viscous effects the model was proposed that the polymer stretching produces a self-consistent effective viscosity changing with the distance from the wall. The linear effective viscosity model was embeded to Navier- Stokes equation, and the drag reduction in wall turbulence flow was computed by using Reynolds stress quation model. The further validation of effective viscosity theory was undertaken by comparing with di- rect numerical simulation results using the FENE-P model under the same flow condition. And the effect of the boundary layer on drag reduction was confirmed by rib strip setting to damage the boundary layer. It is indicated that drag reduction can only be activated in the presence of boundary layer. The bounadary layer is the primary requirement of drag reduction, and the main drag reduction affecting region is likely to be the buffer layer between the viscous sublayer and log-law region.
出处
《力学季刊》
CSCD
北大核心
2013年第1期169-174,共6页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(10672069
11072091)
教育部科学技术研究重点项目(210078)
关键词
壁面湍流减阻
等效粘度
边界层
高分子聚合物
wall-bounded turbulence drag reduction
effective viscosity
boundary layer
polymer
