摘要
为了改善后混合式磨料水射流的切割性能,以固液两相流理论为基础,通过FLUENT模块对喷嘴内磨料的运动进行建模和数值分析。以聚焦管内的单个颗粒为研究对象,优化传统的颗粒相控制模型,获得磨料颗粒在喷嘴内基本的运动情况。研究表明,磨料颗粒吸入混合腔后通过各相之间的碰撞进入高压射流,形成液固两相流。两相流形成初期,磨料颗粒的速度在高压水射流的携带作用下迅速上升。由于混合腔内部结构突变等原因,颗粒相速度浮动较大且处于非稳态。当颗粒通过收敛段进入聚焦管后,颗粒相速度以指数形式逼近射流相速度并逐渐稳定。但由于存在沿程能量损失等因素,颗粒相速度与射流相速度始终存在滑移,最终颗粒相速度仍略小射流相速度。
In order to improve the cutting performance of the post-mixed abrasive water jet,the mathematical model of the abra-sive motion in the focusing tube was established and numerically simulated on the basis of theory of solid-fluid two phase flow by using FLUENT software module. The traditional control model of particle phase was optimized by a researching object of single particle in the focusing tube,and the basic movement condition of abrasive particle in the nozzle was obtained. Research results show that the abra-sive particles join the high-speed jet by the collision between each phase after they enter into the mixing chamber. Therefore two phase jet flow in the end is formed. Under the action of high speed water jet carrying,the speed of the particles will rise rapidly on initial forming stage of the two-phase flow. Due to causes of sudden change of internal structure in mixing chamber,phase velocity of particle has a big difference and is unsteady. After the particles enter into the focus tube through convergence section,the phase velocity of particle will exponentially approach the phase velocity of liquid jet and it will gradually be in steady. But because of causes of linear en-ergy loss along the path,phase velocity of particle has always slide away relatively to that of the liquid jet. The velocity of abrasive par-ticles is slightly slower than liquid jet speed after all.
出处
《机床与液压》
北大核心
2014年第9期109-112,共4页
Machine Tool & Hydraulics
基金
四川省科技厅项目资助(2011JYZ017)
西华大学研究生创新基金资助
