基于等分法和迭代算法的磨料射流速度模型

摘要

针对前混合磨料射流磨料速度模型中存在的磨料受力考虑不全,无法体现磨料加速度、阻力系数以及雷诺数等关键参数的变化等问题,以固液两相流理论为基础,建立了磨料在高压管路、喷嘴内的速度模型,并基于等分法和迭代算法的数值求解方法,求解了磨料速度模型.计算结果与参考文献的平均百分比误差在5%之内,验证了该算法的正确性.同时,利用该速度模型得到了磨料在高压管路和喷嘴内的速度、加速度、阻力系数以及雷诺数的变化规律:高压管路内,磨料速度随磨料运动距离的增加逐渐增大,最后无限接近于水的速度;磨料加速度和雷诺数随磨料运动距离的增加逐渐减小,最后会趋于零;而阻力系数则随磨料运动距离的增加逐渐增大.喷嘴收敛段内,磨料速度随磨料运动距离的增加逐渐增大;磨料加速度、阻力系数以及雷诺数随磨料运动距离的增加有一个先减小后增加的过程.喷嘴直线段内,磨料速度随磨料运动距离的增加逐渐增大;磨料的加速度、雷诺数和阻力系数随着磨料运动距离的增加逐渐减小.%In order to solve the problems,that force analysis is not comprehensive and the results cannot reflect the change of key parameters,such as particle acceleration,drag coefficient and Reynolds number,exist in the existing velocity models of pre-mixed abrasive water jet.Based on the theory of solid-liquid two-phase flow,the velocity model of particle in the high pressure pipeline and the nozzle was established.And the particle velocity model was solved by a numerical solution based on the bisection method and iterative algorithm.The developed models were finally veri-fied by that the model calculations and the corresponding reference data are in good agreement with less than 5% average errors.At the same time,the variations rule of velocity,acceleration,drag coefficient and Reynolds number of the abrasive in the high-pressure pipeline and nozzle have been obtained by using the velocity model: In the high pressure pipeline,the particle velocity increases with the increase of the moving dis-tance of particle,and finally it is infinitely close to the velocity of the water.The particle acceleration and the Reynolds number decrease with the increase of the moving distance of particle,and finally become zero.The drag coefficient increases with the increase of the moving distance of particle. In the convergent section of nozzle,the particle velocity increases with the increase of the moving distance of particle.The particle accel-eration,drag coefficient and Reynolds number have a process of decreasing first and then increasing with the increase of the moving distance of particle. In the straight section of the nozzle,the particle velocity increases with the increase of the moving distance of particle.and the accelera-tion,the Reynolds number and the drag coefficient decrease with the increase of the moving distance of particle.