半封闭冲击射流对移动平板流动特性的影响

Influences of Half Confined Jet on the Properties of a Moving Plate Flow

采用雷诺应力湍流模型和Simplic算法对半封闭湍流狭缝射流冲击移动平板进行了数值分析,得到了不同射角和平板速度下的流场结构、湍流强度和平板面剪切应力分布曲线。结果表明,减小射流倾角和提高平板速度都会导致流场结构和湍流强度相对射流中心线呈现非对称性,且在流场一侧形成二次回流区。当平板速度提高到入口射流速度的2倍时,平板近壁处的湍流强度和平板表面的剪切应力系数显著提高。

A flow field from a half confined slot jet to a moving surface is simulated.The simulation is based on the Reynolds stress turbulence model which is solved sequentially by the Simplic method.The simulation tells relationships between flow properties（such as shape of the flow field,turbulence intensity and local skin friction coefficient at the surface of the plate） and control parameters（such as jet angle and plate velocity）.Further analysis of the relationships reveals that both the shape of the flow field and the distribution of the turbulence intensity become asymmetric when the jet angle is decreased or when the plate velocity is increased;the decrease of the jet angle or the increase of the plate velocity brings a secondary recirculation zone at one side of the flow field;the turbulence intensity near the wall and the local skin friction coefficient at the plate surface increase significantly when the plate speed reaches the twice of the inlet speed of the flow.