水科学进展2013，Vol.24Issue(1)：95-102,8.
基于模式匹配法的明渠紊流涡结构分析
Analysis of vortex structure in open channel turbulence based on model matching
摘要
Abstract
A novel scheme was proposed for identifying and extracting vortex structures from two-dimensional velocity fields. The new scheme involves no threshold values and requires a lower spatial resolution than velocity-gradient based methods. The scheme was used to analyze the characteristics of vortex structures based on two-dimensional velocity data measured with particle image velocimetry in a turbulent open channel flow. The educed parameters show that population density and vorticity of spanwise vortex decrease along the wall-normal direction while the radius tend to increase all the way. In addition, vortex strength represented by the circulation stabilizes after a quick increase in the inner region. Comparison demonstrates that population density of the prograde vortex is larger than that of the retrograde one and the prograde vortices exhibit stronger swirl motion. Conditionally averaged velocity fields of vortical structures statistically verify the existence of hairpin vortex packets and the spatial correlation of retrograde-prograde vortices in open channel turbulence.关键词
涡结构/涡识别/模式匹配/明渠紊流/顺向涡/逆向涡Key words
vortex structure/ vortex identification/ model matching/ open channel turbulence/ prograde vortex/ retrograde vortex分类
建筑与水利引用本文复制引用
陈启刚,李丹勋,钟强,王兴奎..基于模式匹配法的明渠紊流涡结构分析[J].水科学进展,2013,24(1):95-102,8.基金项目
国家自然科学基金资助项目(51127006) （51127006）
"十二五"国家科技支撑计划资助课题(2012BAB04B01) （2012BAB04B01）
