【摘要】 利用声学多普勒流速仪(Acoustic Doppler Velocimetry,ADV)自动测速系统和平面激光诱导荧光(Plane Laser In-duced Florescence,PLIF)系统对同向圆射流的速度场和浓度场进行了系统的研究,并与前人的工作进行了比较和讨论。时均特性测量结果表明,射流主体段下游各断面的速度和浓度横向分布是自相似的,且近似可用高斯分布来表示;随着射流向下游传播,射流中心流速逐渐衰减,在强射流区和弱射流区遵循不同的规律;紊动特性测量结果表明,下游各断面的紊动强度横向分布是自相似的。更多还原

【Abstract】 In this paper,the new measuring system,including the Acoustic Doppler Velocimeter(ADV) technique,the plane laser induced fluorescence(PLIF) technique and the laboratory virtual instrument(Labview) technique,are employed to measure the quantitative time-averaged and turbulent velocity fields and the scalar concentration fields of a round jet issuing into a co-flowing current.The spreading and mixing characteristics of a round jet in a co-flow are discussed and compared with the works done before.The experimental results show that the radial distributions of dimensionless mean excess velocity,concentration and turbulent intensity at the different downstream location are self-similar and the distributions of velocity and concentration are overlapping to the Gaussian curve.The jet centerline velocity decays along with downstream distance increasing and follows different laws in the strong and weak jet region.更多还原