激光穿孔中辅助气体动力学性能分析  

Dynamic Characteristic Analysis of Impinging Jet in Laser Drilling

作　　者：胡俊[1] 郭绍刚[1] 罗磊[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：《中国激光》2008年第8期1250-1254,共5页Chinese Journal of Lasers

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：通过基于结果的自适应算法对激光穿孔过程中的撞击射流场结构进行了计算.辅助气体与工件之间相互作用的本质过程可以描述为轴对称撞击射流过程,高压气体的轴对称撞击射流可以展示在高压状态下气体与工件之间的相互作用.气体射流与工件相互作用时,入射斜波与正激波发生直接接触和非接触的两种不同状态,分析了高压气体辅助激光切割第二个合理的加工区域的存在原因,加工参数对切口中气体动力学性能的影响,以及分析高压气体辅助加工能力随工件与喷嘴距离之间的关系.通常在入射斜波与正激波直接相互作用没有完成时,质量流率随工件与喷嘴距离变大而剧烈衰减,因此高压气体辅助激光切割时要尽可能保证工件与喷嘴的距离限定在合理的范围内.The interaction of an impinging jet in laser drilling is carried out using an explicit, coupled solution algorithm with solution-based mesh adaptation. The essential process of gas jet-workpiece interaction can be described through the description of axisymmetrical impinging jet. It is completely shown that there are two states including contact and separation between the incident shock and the normal shock in gas jet-workpiece interaction. At the same time, this paper shows the reason for the existence of the second reasonable ranges of laser cutting. The effect of processing parameter on dynamic characteristic is analyzed, and this paper also analyzes the relationship between machining capacity of assist gas and standoff distance. The mass flow rate decreases rapidly with the increase of standoff distance before the end of direct interaction between the incident shock and the normal shock, so the standoff distance should be set in reasonable ranges.

关 键 词：激光技术 激光穿孔 撞击射流 正激波 动力学性能 

分 类 号：TG485[金属学及工艺—焊接]