会聚型喷嘴是目前激光切割应用最为广泛的亚音速喷嘴, 所产生的流场结构对激光切割质量和效率影响显著。建立了会聚型喷嘴的湍流模型, 根据可压缩流体轴对称N－S方程, 采用结构网格和二阶精度的有限体积法, 对不同内部形状参数的会聚型喷嘴自由射流进行了数值模拟。揭示锥型喷嘴收缩段收缩角、收敛型喷嘴收敛段抛物线曲率半径对射流的流场结构参数的影响规律, 为激光切割喷嘴的优化选择和设计提供有效依据。

Assemble nozzles are most widely used in the laser cutting presently, and their resulted jet structure influences laser cutting quality and efficiency remarkably. Based on the axial symmetric N-S equation of compressible liquid, we establish the onflow model to simulate convergent nozzles’ free jet with different internal parameters by using structural grid and finite volume of quadratic precision. The law of the influence of contractive angle of taper nozzles and curvature radius of convergence nozzles’ convergent section on jet structure parameters is revealed, and it can provide a basis for optimization selection and design about laser cutting nozzles.