激光切割中的超声速喷嘴辅助气体流场分析与结构改进  

Analysis of Assistant Gas Flow Field and Structure Improvement of Supersonic Nozzle in Laser Cutting

作　　者：胡俊[1] 郭绍刚[1] 邱明勇[1] 姚振强[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《机械工程学报》2009年第6期251-255,共5页Journal of Mechanical Engineering

基　　金：上海市科学技术发展基金光科技重大专项(05DZ22003);上海市科学技术发展基金登山计划(06DZ11418)资助项目

摘　　要：激光切割过程的实现是高能激光束与辅助气体相互作用的结果,喷嘴内部形状及其产生的流场特征是影响激光切割质量和效率的关键因素之一。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,分析激光切割的超声速喷嘴辅助气体射流场结构与喷嘴喉部转角的关系,以及研究发散段长度对流场状态参数的影响规律,通过合理规划喉部转角与发散段长度,采用小斜线段代替复杂曲线,简化超声速喷嘴的结构。仿真结果表明,该结构喷嘴可以获得合理辅助气体出口参数与动力学性能良好的射流场结构。The implementation of laser cutting is the interaction result of laser beam and assistant gas, so the inner shape of nozzles and their flow field is one of the key factors of affecting laser cutting quality and efficiency. Based on the axial symmetric N-S equation of compressible fluid, structure network and finite volume method with second order accuracy are adopted to analyze the relationship between the structure of jet flow field and the turning angle of throat section, and the influence of the length of divergence section on state parameters of flow field is studied. Through rationally planning the turning angle of throat section and the length of divergence section, short oblique line is used to replace the complex curve so as to simplify the structure of supersonic nozzle. The simulation results show that the improved nozzle can obtain a jet flow field with rational assistant gas outlet parameters and good dynamic performance.

关 键 词：超声速喷嘴 喉部 射流场 

分 类 号：TG485[金属学及工艺—焊接]