T型通道内阵列缝隙弱抽吸流动实验研究

Experimental Study on Weak Suction in Turbulent T-junction Flows With Array Blades

以T型通道为基本模型,考查其交接面处安装横向阵列叶片作用下的支流的湍流流场。采用粒子图像速度场仪(PIV),对不同主流速度和抽吸比工况下支流下游流场进行了实验测量,通过对粒子图像计算处理得到了支管中心截面在不同实验工况下的瞬态矢量-速度云图及瞬态涡量-流线云图。所考察的主流速度范围是30.0~50.0 m/s,速度比的范围是0.08~0.18。实验观察到在T型通道支路靠近上壁面一侧存在与支路气流方向相反的回流流动,并产生了明显的旋涡串现象,该区域速度较小且回流区的范围超过一半流道面积;顺流高速区主要位于支管下壁面附近;主流速度和抽吸比较大时支管流动较为均匀.

In the present paper, the turbulence flow fields of branch duct are examined in T-junction channel with horizontal array blades. The downstream flow field of branch duct is experimentally investigated by PIV （Particle Image Velocimetry） system under different cross velocities and velocity ratios. The distributions of instantaneous vector-velocity and vorticity-streamline of branch duct are figured up by the calculation of the particle image under different experimental conditions. The range of mainstream speed is 30.0-50.0 m/s and the range of velocity ratio is 0.08-0.18. It is observed that the airflow direction near the upper wall in T-junction channel is opposite to the direction of suction in branch duct, that is to say, there exits obvious vortex series and recirculation phenomena, where there is low velocity zone which occupies more than half the channel area. The region of high velocity is mainly located near the down wall of the branch duet. Moreover, the fluid velocity is more uniform as the main flow velocity and/or velocity ratio increases.