前混合式磨料水射流磨料粒子加速过程数值模拟

发布时间：2019-02-15 22:04

【摘要】：针对前混合式磨料射流磨料加速过程运动复杂、实验研究困难及有限元处理超大变形存在网格畸变等问题,基于光滑粒子(SPH)耦合有限元(FEM)方法模拟前混合式磨料射流喷嘴不同阶段磨料粒子加速特征及磨料射流破碎靶体全过程。其中水介质用SPH建模,磨料粒子、喷嘴、靶体等用FEM建模。揭示磨料粒子群在喷嘴中的运动轨迹及喷嘴结构对磨料粒子加速影响规律。研究表明,磨料粒子进入喷嘴收敛段之前已基本达到与水介质相同速度,进入收敛段后因与水介质存在速度差使其获得加速,但与水介质速度差逐渐增大;进入直线段后水介质与磨料粒子一直加速,且水介质速度在直线段末端趋于稳定,在离开喷嘴的短距离范围内水介质速度趋于稳定,磨料粒子在核心段水流作用下继续加速,最终趋于稳定;磨料粒子群在喷嘴收敛段相互碰撞运动剧烈,进入直线段后相对平缓;流量一定下磨料粒子速度随喷嘴收敛段延长而增加,但增加有限;随直线段延长而增加,增加显著。数值模拟结果与相关文献吻合较好。
[Abstract]:In view of the complex acceleration process of abrasive with pre-mixed abrasive jet, the difficulty of experimental research and the mesh distortion in the treatment of super-large deformation by finite element method, etc. Based on smooth particle (SPH) coupled finite element (FEM) method, the acceleration characteristics of abrasive particles in different stages of pre-mixed abrasive jet nozzle and the whole process of abrasive jet crushing target were simulated. Water medium is modeled by SPH, abrasive particle, nozzle and target are modeled by FEM. The movement trajectory of abrasive particle swarm in nozzle and the influence of nozzle structure on abrasive particle acceleration are revealed. The results show that the abrasive particles have reached the same speed as the water medium before entering the nozzle convergence section, but the velocity difference between the abrasive particles and the water medium increases gradually because of the difference between the velocity of the abrasive particle and the water medium. After entering the straight line, the velocity of water medium and abrasive particle accelerates continuously, and the velocity of water medium tends to be stable at the end of the straight section, and the velocity of water medium tends to be stable in the short distance from the nozzle, and the abrasive particle continues to accelerate under the action of the core section. Finally, it tends to be stable; The abrasive particle swarm collides with each other in the convergent section of nozzle and is relatively smooth after entering the straight section; the velocity of abrasive particle increases with the nozzle convergence section but the increase is limited under a certain flow rate; with the extension of the straight section the abrasive particle velocity increases significantly. The numerical simulation results are in good agreement with the related literatures.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室;
【基金】：国家重点基础研究发展计划资助(2014CB239206) 国家自然科学基金青年基金项目(51404045) 长江学者和创新团队发展计划资助(IRT13043) 中国博士后科学基金项目(2014M552322) 中央高校基本科研业务费科研专项(CDJZR12248801)
【分类号】：TG664

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