【摘要】 湍流冲击射流在工程和军事工业中都具有广泛的应用。采用粒子图像测速(PIV)技术,在射流雷诺数为20000和喷口-冲击板间距为4倍喷管水力直径的条件下,对矩形管湍流冲击射流场进行了实验测量,得到了主射流区和冲击区附近测量截面上的平均速度和涡量分布。结果表明,由于射流的卷吸及其与环境流体之间的相互作用,使得射流边界处具有很高的涡量;在流场的流出区域存在一个显著的回流区,这是半封闭冲击射流场的特征结构之一。更多还原

【Abstract】 Turbulent impinging jets are widely used in engineering and military industrial field. The flow field of a rectangular turbulent impinging jet has been measured experimentally by the PIV technique. The experiment has been carried out for Reynolds number of 20000 and for nozzle-to-plate spacing of four times of the hydraulic diameter of the jet pipe. Distributions of average velocity and vorticity on different cut planes located in the main jet region and the impingement region have been obtained. It has shown from the experimental results that the vorticity near the jet boundary region is high in magnitude due to the interaction between the jet fluid and the entrained ambient fluid. An obvious recirculation zone has also been found in the outflow region of the field, which is one of the characteristics of the semi-confined impinging jet flow field.更多还原