A simplified model for flows with eddies in symmetrically expanding channels
- 作者：Shinya Watanabe ; Vakhtang Putkaradze
- 关键词：Channel flow ; Dimension reduction ; Analysis ; Aperiodic flow pattern
- 刊名：Physics Letters A
- 出版年：2007
- 期刊代码：57_03759601
- 类别：ph
- 出版时间：8 October 2007
- 卷：370
- 期：1
- 页码：58-63
- 文件大小：266 K
摘要
We derive a simplified model for two-dimensional (2D) channel flows with recirculated regions at moderate Reynolds numbers based on an extension of the boundary layer (BL) theory and averaging across the channel. The model reproduces symmetry-breaking bifurcations and resulting flow structures accurately. Analytical estimates for the decay rates toward the parabolic profile before and after a sudden change in the walls agree well with the full numerical simulations. A seemingly chaotic steady flow is also discovered in a channel with periodic expansions and contractions.