等腰三角形湍流射流的流动特性实验研究  

Experimental Investigation of Flow Characteristics Issuing from Isosceles Triangular Orifices

作　　者：栾剑[1] 徐敏义[1] 马梓然 李敏[1] 刘晓鹏[1] LUAN Jian XU Min- yi MA Zi- ran LI Min LIU Xiao-peng(Marine Engineering College, Dalian Maritime University, Dalian 116026, China)

机构地区：[1]大连海事大学轮机工程学院,辽宁大连116026

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)

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.

关 键 词：非圆形射流 多尺度 频谱 热线风速仪 

分 类 号：O358[理学—流体力学]