Optimal Design Of 3D Variable Cross-section Stator And Rotor For 73mm Turbodrill

Micro-hole drilling technology is an efficient,low-cost,and environmentally friendly cutting-edge drilling technology.It is a new way to increase oil and gas recovery using drilling methods,and has broad application prospects.At present,China’s research in this field is in the early stage,and there is still a large gap compared with foreign developed countries,especially in micro-hole drilling tools and key supporting technologies.This paper optimizes the design parameters of the stator and rotor blade structure of the Φ73mm turbodrill suitable for Φ88.9mm tiny boreholes in order to improve its hydraulic efficiency,increase output torque and reduce energy loss.The design of the turbine blade structure mainly includes two-dimensional cross-sectional profile design and three-dimensional curved surface modeling design.Based on the investigation of the traditional design basic theory and modern design methods of turbodrill at home and abroad,this paper uses cubic polynomial to design the two-dimensional section profile of the turbine blade,and uses line projection to design the three-dimensional variable section of the blade.After design of various structural schemes with stator and rotor blades,the exclusive computational fluid dynamics software of the impeller machinery NUMECA is used to numerical simulation.The optimal scheme with high hydraulic efficiency,large output torque and small energy loss is selected: rotor blade height 8.5mm,installation angle 67 °,blade number 14;stator blade height 8mm,installation angle 42 °,blade number 10.On this basis,choose the bow angle and sweep angle of the Φ73mm turbodrill rotor within a reasonable range respectively for optimization.The numerical simulation results show that the hydraulic efficiency of the positive-bowed blade is higher than that of the negative-bowed blade,and the optimal bow angle of the rotor is 5 °,and the optimal sweep angle of the rotor is-10 °.