摘要
为了克服组合双射流的缺点,提出了新型双射流喷嘴,并采用RNGκ-ε湍流模型计算了新型双射流喷嘴冲击井底的流场。建模时采用有限体积法离散各控制方程,采用松弛迭代法求解各离散方程,壁面采用无滑移固壁边界。模拟结果表明,新型双射流不存在等速核,且轴心线冲击力小,但作用面积大;与旋转射流相比,轴心线附近流速最大,从而实现了高效破岩。漫流层的径向流速最大值出现在距离外流场轴线2.5D距离处,大小约为喷嘴出口速度的23%。新型双射流利用圆形射流冲击和旋转射流剪切破岩,能形成直径较大、深度较大的破碎坑。
In order to address the deficiency of the combined dual-jet, a novel dual-jet nozzle is proposed. The flow field of the novel dual-jet nozzle jetting on bottomhole is calculated by using RNG κ-ε turbulence model. The governing equation is discretized by finite volume method and then solved by relaxation iteration method. The wall is treated as no-slip wall boundary. Simulation results show that the novel dual-jet has no potential core and has a small jetting force at axis but has a large action area. Compared with the rotating jet, the new dual-jet has the maximum flow rate at the axis, thus achieving a high efficient rock breaking. The maximum radial flow velocity of overflow layer is happened at 2. 5D away from the outflow field axis with the velocity about 23% of the nozzle exit velocity. By making a round and a rotating jetting, the novel dual-jet could make the crushed pits larger and deeper.
出处
《石油机械》
北大核心
2014年第9期11-14,18,共5页
China Petroleum Machinery
基金
国家973计划课题"深井复杂条件钻井设计平台与风险控制机制"(2010CB226706)
关键词
新型双射流
井底流场
旋转射流
轴向速度
射流喷嘴
等速核
novel dual-jet
bottomhole flow field
rotating jet
axial velocity
jet nozzle
potential core
