摘要
通过波瓣喷管引射-混合器的流场三维数值计算,得到了流向涡和正交涡产生、衰减的演变以及对混合效率的影响规律,进一步揭示了波瓣喷管有利于强化引射能力和混合效率的内在机理。结果表明:喷管出口流向涡的尺度基本与波瓣的高度相当,流向涡可以诱发主流和次流之间强烈的对流混合,在喷管下游一倍混合管直径的混合距离内强化混合作用显著,随着流向涡向下游发展,涡强衰减迅速;正交涡具有与波瓣尾缘一样的几何外形,在混合管下游,由于主流和次流之间的速度梯度下降,正交涡的强度显著降低,对强化混合的影响不大。
Three-dimension flow fields in the lobed mixer-ejector is numerically investigated, with main focus on vortical structures as well as vortical characteristics, to reveal further mechanism of the lobed mixer-ejector on enhanced mixing efficiency and pumping capacity. The results show that ： （ 1 ） the scale of streamwise vortices at the trailing edge of lobed nozzle is about the lobe height, the important contribution of the streamwise vortices for enhanced mixing occurs in downstream distance away from nozzle exit about one mixing duct diameter and then the intensity of streamwise vortices decays obviously; （2） the normal vortices take on lobed shape near the trailing edge of lobed nozzle, the normal vortices intensity decreases rapidly downstream, and have a little effect on enhanced mixing efficiency. These results are verified with the physics nature.
出处
《空气动力学学报》
EI
CSCD
北大核心
2005年第3期355-359,共5页
Acta Aerodynamica Sinica
关键词
波瓣喷管
混合器
数值计算
流向涡
正交涡
lobed nozzle
mixer
numerical computation
stream-wise vortices
normal vortices
