直旋混合射流内流场的特性研究

Mixing Mechanism of the Flow Field in a Straight-turn Hybrid Jet

自进式钻头是径向射流钻井技术中的一个不可或缺的组件。然而,目前国内外对直旋混合射流进行的研究多数是关于其外流场对破岩效率的,而对组合射流的形成机理的研究较少。通过在非淹没条件下进行了新型直旋混合射流的内部流场仿真,得到了内流场的混合特性:轴向速度靠近轴心处速度最大,切向速度则是沿着射流的不断混合呈现正弦曲线分布的规律。结果可为进一步研究钻头的破岩特性、机理和优化设计提供理论依据。

Self-advancing drill bits are an indispensable component in radial jet drilling technology.However,at present,most of the research on the direct rotation mixed jet at home and abroad is about the efficiency of its external flow field on rock breaking,while the formation mechanism of the combined jet is less studied.By simulating the internal flow field of the new direct rotation hybrid jet under non-submerged conditions,the formation mechanism of the internal flow field is obtained.The axial velocity near the axis center is the largest velocity,and the tangential velocity is the law of sinusoidal distribution along the continuous mixing of the jet.The results of this study can provide a theoretical basis for further research on the rock breaking characteristics,mechanism and optimization design of drill bits.