立体旋流筛板空间气相流场的CFD模拟

Computational fluid dynamic simulation of gas flow field in tridimensional rotating sieve tray

应用STAR-CCM+软件,采用Realizable k-ε模型,对立体旋流筛板空间气相流场特性进行了数值模拟研究。结果表明:立体旋流筛板空间主要存在贴近筛板壁面的穿孔流动与两筛板间的旋流流动2种方式,气体经立体旋流筛板的流动过程分起旋阶段与旋流发展阶段。在贴近筛板壁面的区域,由内筒外壁至外筒内壁方向,穿孔流动速度在各流动阶段均呈增加的趋势;在两筛板间区域,起旋阶段,由内筒外壁至外筒内壁方向旋流流动速度值变化较小,沿旋流方向靠近下一块筛板区域的速度值较大;旋流发展阶段,由内筒外壁至外筒内壁方向旋流流动速度值呈先降低再增加的趋势,沿旋流方向靠近上一块筛板区域的速度值较大。在轴向不同高度区域,贴近筛板壁面的穿孔速度为中部最大、上部次之、下部最小;两筛板间的旋流流动速度为上部较小,中、下部较大。各区域速度值随着气相动能因子的增加而增加。

Making use of the STAR-CCM ＋ software and Realizable k-e turbulence model, numerical simulation of gas flow field in the tridimensional rotating sieve tray was investigated with varying gas kinetic energy factor. The simulation results showed that, the space of tridimensional rotating sieve tray mainly existed two flow ways that perforation flow closing to sieve plate wall and rotating flow between the two sieve plate; gas flow process in tridimensional rotating sieve tray was divided into rotary and swirl development stage. Nearing the plate wall, the perforation flow velocity showed increasing trend in the fluid phase from the external wall of internal cylinder direction to the internal wall of the outer cylinder. In the region between two sieve plates, rotating velocity had small changes from the external wall of internal cylinder direction to the internal wall of the outer cylinder and velocity was larger near the next plate along the rotating direction in rotary stage. In the swirl development stage, the swirl flow velocity was firstly decreased and then increased, and the velocity was larger near the upper sieve plate along the swirl flow direction. In the different height of axial, closing to the wall surface of the sieve plate perforation velocity was that the largest value in the middle and the top part took second place, and the under-part was minimum one; Swirl flow velocity between two sieve plate was the smaller value on the top and the middle and under-part was larger. The regional velocity increased with increasing gas kinetic energy factor.