Abstract: The fluctuation, velocity distribution and spread rate of the radial jet from two opposed nozzles at L/D＝0.5—100 were experimentally investigated and numerically simulated, whereL is the length of two nozzles separation and D is the nozzle diameter.Results show that the turbulence intensity of the radial jet is obviously higher than that of free jet.The velocity of the radial jet increases to a maximum from the stagnation point then decays and exhibits a selfsimilarity.With the increase of the nozzle separation, the spread rate of the radial jet increases, and is about 1.5—3 times as that of free round jet.The velocity distributions of the radial jet from two opposed nozzles were numerically simulated by CFD.Compared to experimental results, the spread rate is obviously underpredicted by two-equation turbulence models, and the prediction by Reynolds stress model (RSM) is improved..

Key words:

两喷嘴对置撞击流, 径向射流, 扩展率, 热线风速仪

摘要：

对喷嘴间距与喷嘴直径比为0.5～100范围内两喷嘴对置撞击流径向射流的湍流脉动特征、速度分布和扩展率等进行了实验研究和数值模拟。研究结果表明，撞击流径向射流明显较自由射流湍动强烈;从驻点开始径向射流速度逐渐增大到最大值后开始衰减，射流呈现自相似性;随着喷嘴间距增大，撞击流径向射流的扩展率呈现增大的趋势，大约为自由圆射流的1.5～3倍。采用CFD软件对撞击流径向射流的速度分布特征进行了数值模拟，与实验结果相比，两方程湍流模型预报的撞击流径向射流的扩展率明显偏小，雷诺应力模型的预报精度有较大改进。

关键词:

两喷嘴对置撞击流, 径向射流, 扩展率, 热线风速仪