摘要
设计了一种水垫式旋转磨料射流喷嘴,并对其内部流场流动特性进行了数值研究。采用高精度QUICK离散格式离散了雷诺平均的N_S方程和Realizablek_ε紊流模型,求解了喷嘴的内部流场,同时利用拉格朗日的方法对磨料颗粒的运动轨迹进行了追踪。该模型用同轴射流旋流燃烧室算例进行了验证,计算结果和实验值相吻合,表明适用于旋流流场的计算。喷嘴流场计算结果表明,流量比(切向与轴向入流流量之比)是决定喷嘴内流动状态的重要参数,喷嘴出口旋流数随流量比的增大而增大,并逐渐趋于一定值,磨料颗粒在喷嘴内的运动特性受流量比及磨料颗粒的粒径和密度影响较大。通过研究表明,对流量比以及磨料颗粒进行优选,能够获得破岩效果较好的旋转磨料射流,并且减少磨料颗粒对喷嘴的磨蚀,保证喷嘴的使用寿命。
A new type of nozzle generating swirling-abrasive water jet has been designed and the numerical method is employed to analyze the characteristics of the jet flow in the nozzle. The flow patterns are obtained by solving Reynold-averaged Navier-Stokes equations and Realizable κ-ε turbulent model with high-accuracy QUICK scheme. The tracks of the abrasive particles are traced with Lagrange method. The mathematical model is tested by computing the swirl combustor with coaxial jets. The calculation results are coincident with the experimental data and it shows that the model is applicable to swirling flow. The flow results in the nozzle have shown that flow rate ratio of tangential inflow and axial inflow is one of the most important factors of the flow control, and the swirl number at the outlet will become larger as the flow rate ratio increases. Moreover, the size and density of abrasive particles also have important influence on the motion of particles. The results have also shown that the swirling-abrasive jet flow, which breaks the rock high-efficiently and wears down the inner wall of the nozzle low-extensively, can be generated by adjusting the flow rate ratio and choosing the right diameter and density of the abrasive particles.
出处
《水力发电学报》
EI
CSCD
北大核心
2006年第6期111-118,共8页
Journal of Hydroelectric Engineering
基金
国家自然科学基金资助项目(50379018)
