壁面的表面粗糙度引起的Stokes层亚临界不稳定性

孔玮; 罗纪生

doi:10.13224/j.cnki.jasp.2016.10.025

壁面的表面粗糙度引起的Stokes层亚临界不稳定性

doi: 10.13224/j.cnki.jasp.2016.10.025

孔玮^1,2,
罗纪生¹

1. 天津大学机械工程学院力学系, 天津 30007;
2. 淮阴工学院建筑工程学院, 江苏淮安 223001

基金项目:

国家自然科学基金（11202147，11332007）；高等学校博士学科点专项科研基金（20120032120007）

详细信息

作者简介:
孔玮(1986-),男,安徽潜山人,博士生,主要从事流动稳定性及转捩方面的研究.

中图分类号: V211.1;O351.2
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- 文章访问数: 718
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- 被引次数: 0
出版历程
- 收稿日期: 2015-10-29
- 刊出日期: 2016-10-28

Subcritical instability of Stokes layer induced by wall surface roughness

KONG Wei^1,2,
LUO Ji-sheng¹

1. Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 30007;
2. Faculty of Architecture and Civil Engineering, Huaiyin Institute of Technology, Huaian Jiangsu 223001, China

摘要

摘要: 用数值模拟的方法研究了二维壁面的表面粗糙度下Stokes层的非线性亚临界不稳定性问题.发现当粗糙度高度极小时，响应系数曲线与线性情况就会产生较大偏离.随着粗糙度高度的增加，扰动1阶谱会出现亚谐波的成分，粗糙度高度的进一步增加使扰动1阶谱进入混乱阶段，显示出亚临界失稳的过程.根据粗糙度高度与扰动1阶谱演化的特征关系，定义了临界粗糙度高度，并给出临界粗糙度高度与雷诺数的关系曲线.结果表明：临界粗糙度高度随着雷诺数增大而减小.雷诺数为300左右时，微米量级的粗糙度高度就可能引起Stokes层的亚临界失稳，发生转捩，由此也可以给出实验中观测到的转捩通常都发生在雷诺数为300附近的原因.
- Stokes 层 /
- 表面粗糙度 /
- 非线性响应曲线 /
- 亚临界不稳定性 /
- 转捩
Abstract: The subcritical instability problem of a finite Stokes layer over two-dimensional wall surface roughness was investigated by numerical simulations. Results indicated that infinitesimal height of roughness led to a quite large deviation of the response curves from the linear cases. With the increasing height of wall roughness, the evolution of the disturbance at one order spectrum displayed the sub-harmonic component, and then the evolution entered into the irregular state, indicating the subcritical instability. According to the correlation between the height of roughness and the disturbance at one order spectrum evolution, the critical height of roughness was defined, and the relation curve was given as a result. Results shows that the critical height of roughness becomes smaller as the Reynolds number increases. At the Reynolds number around 300, the height of roughness of just the level of micrometer would be able to trigger the subcritical instability and transition in Stokes layer. That is why transition often occurs in experimental observations at Reynolds number around 300.
- Stokes layer /
- surface roughness /
- nonlinear response curve /
- subcritical instability /
- transition

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