Abstract: Subsonic normal and oblique impinging jet were predicted by three dimensional compressible Navier Stokes equations. A finite volume method with unstructured meshes and RNG k ε turbulence model were employed in the calculation. The characteristics of three regions, free flow, stagnation region and wall stress flow in normal impinging flow were simulated. The entrainment near impinging region and reverse flow were shown in the calculating results, which were coincided with those of experiment. From the distribution of velocity, a great velocity gradient can be seen in the zone with 2 D distance to the wall. The phenomenon was due to the boundary flow and reverse flow near the wall. The maximum velocity component near the wall and the maximum total pressure shift from the impinging point.

Key words: Finite volume method;Unstructured mesh;Impinging jet;Turbulent jet;Mathematical simulation

摘要： 利用有限体积法对三维可压缩的N S方程进行离散 ,对喷嘴的亚声速垂直冲击射流和斜冲击射流进行了数值模拟。网格的划分采用非结构性网格 ,湍流模型为RNGk ε湍流模型 ,在近壁处采用壁面函数进行修正 ,流场计算结果与实验值吻合一致。计算可得到垂直冲击流场结构的三个区域 :自由射流、滞止区和壁面射流区域 ,并显示出垂直冲击点附近区域的卷吸回流、速度分布。冲击射流近壁处存在着回流现象 ,由于边界层流动和近壁回流引起距离固壁 2D内的速度梯度变化较大。斜冲击在近壁处平行壁面速度的最大值 ,以及壁面上的总压最大值都偏离冲击点 ,并且相对应

关键词: 有限体积法;非结构网格;冲击射流;湍流射流;数学仿真