摘要
对喷嘴等效直径相同出口Reynolds数均为15000的3种等腰三角形(顶角分别为30,60和90°)以及圆形孔口射流进行了流场显示与速度场测量.结果表明:相比于圆形射流,等腰三角形射流的出口中心线速度衰减更快,湍流度更高,三角形射流卷吸周围流体能力显著增强.随着三角形顶角减小,近场区涡结构三维性更强,卷吸效果更明显.此外,对不同射流的中心线湍动能谱概率密度函数Taylor尺度和Kolmogorov尺度进行了分析讨论,发现出口形状对湍流小尺度运动的影响较小.
The present study systematically investigated the statistical properties of the free air jets issuing from isosceles triangular orifices with apex angles of 30, 60 and 90°. The velocity was measured by a hot-wire anemometer at the exiting Reynolds number （ Re） being 15000 for all jets, based on the equivalent diameter of the triangular orifices. The results show that the centreline mean velocity decays faster and turbulence intensity grow-s higher as AR decays. With jet flows de-veloping downstream, the turbulence energy spectrum, probability density function and turbulence length scales of triangular jets approach to those of circular jets.
作者
栾剑
徐敏义
马梓然
李敏
刘晓鹏
LUAN Jian XU Min- yi MA Zi- ran LI Min LIU Xiao-peng(Marine Engineering College, Dalian Maritime University, Dalian 116026, China)
出处
《气体物理》
2017年第2期37-46,共10页
Physics of Gases
基金
国家自然科学基金(51506019)
辽宁省自然科学基金(2012025012)
关键词
非圆形射流
多尺度
频谱
热线风速仪
non-circular jets
multi-scale
spectrum
hot-wire anemometer
