【摘要】 为了研究ＰＤＣ钻头条件下圆喷嘴射流撞击井底流场的基本规律，在分析ＰＤＣ钻头的基本水力结构特点的基础上，建立了ＰＤＣ钻头条件下并底结构的物理模型。采用ｋ－ε双方程模型封闭湍流Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程，利用求解压力耦合方程的半隐式方法，对这一物理模型条件下的流场进行了数值模拟，并将数值结果与实验研究结果进行了对比。结果表明，所建立的控制方程、控制条件以及所采用的数值方法是合理的根据数值结果，研究了ＰＤＣ钻头条件下，射流撞击井底时的流场结构、轴心速度变化规律以及井底漫流的流动规律。更多还原

【Abstract】 A physical model of the bottomhole structure was developed to study thebottomhole flow field of axisymmetric impinging jets for PDC bits.Numerical simulations onthe flow were done by solving the closed Navier-Stokes equation with k-ε turbulence modeland SIMPLE procedure. Good agreements between the numerical and the experimental resultsshowed that the control equations,control conditions and numerical approaches werereasonable. The compositions of the flow field, attenuation of centerline velocity andcharacteristics of cross-flow at the bottomhole of the impinging jets were investigated by theuse of the numerical results.更多还原