摘要
本文采用动网格技术,利用大涡模拟求解三维N-S方程,对直射流以及倾斜角为30°的斜射流进行了三维数值模拟。数值模拟结果表明:数值模拟的直射流出口速度曲线与理论速度曲线吻合较好,通过直射流与斜射流对比发现,直射流产生的涡环为对称涡环,而斜射流的为不对称涡环;直射流射流出口时均速度影响范围大于斜射流,但是其射流宽度小于斜射流射流宽度。本文还分析了射流与主流的相互作用,数值模拟了不同主流速度下射流的运动状态,结果表明:主流速度为2.0 m/s时,直射流产生的涡环受到主流的作用发生倾斜,斜射流产生的涡环由于主流的作用,变成典型的马蹄涡形式;由于射流对主流的影响,直射流对主流速度起阻碍作用,减缓了边界层及附近主流的速度,斜射流加速了主流边界层内的流体速度,使边界层速度更加饱满;随着主流速度的提高,射流产生的涡环被主流吹扫进入边界层,在壁面上发生破裂,与边界层内流体混合,射流对主流的的影响减弱。
In this paper,Dynamic mesh method,large-eddy simulation were used to study synthetic jet with 90 °and 30 °tilt angle, the three-dimensional viscous unsteady Navier-Stokes equations were solved to simulat the flow of Synthetic jet. The result show that： the velocity curve of perpendicular jet orifice agree well with the theoretical velocity curve （sine curve）, and therefore this method could be used to simulate three-dimensional synthetic jet flow. Comparison on perpendicular synthetic jet and oblique synthetic jet, it is show that the vortex ring generated by perpendicular jet is symmetric, the vortex ring generated by oblique jet is asymmetric; the influence scope of perpendicular jet is father than oblique jet in jet direction, but the jet width of oblique jet is larger than perpendicular jet. Interaction between synthetic jet and different velocity crossflow were also studied in this paper, the results show that： crossflow velocity is 2.0 m/s, as the effect of crossflow, for perpetual jet , the vortex ring is inclined and the top of vortex ring is dissipated; for oblique jet , the bottom of vortex ring is forced onto orifice plate, and it become a typical horseshoe vortex. The results also show that： perpendicular jet hinder the flow of crossflow, it will slow down the velocity of boundary layer and near field flow, but for oblique jet, as it has component in the direction of crossflow, it will accelerate boundary layer flow and boundary layer velocity will become plump.With the increase of crossflow velocity, vortex ring is more and more blew into boundary layer, ruptured at orifice plane and mixed with boundary layer flow, the effect of jet on crossflow is decreased with the increase of crossflow velocity.
出处
《安徽建筑大学学报》
2017年第3期41-46,共6页
Journal of Anhui Jianzhu University
基金
安徽省高校自然科学研究项目(KJ2017A807)
关键词
合成射流
动网格
主流
相互作用
大涡模拟
Synthetic Jet
Dynamic Mesh Method
Crossfow
Interaction
Large-Eddy Simulation
