Study On Turbodrill Bowed-twisted Blade Design And Hydraulic Performance

Turbodrill is a kind of downhole power drilling tools with special structure.Its main working elements are turbine stator and rotor,and its function is to transform high-pressure drilling fluid energy into mechanical energy on main shaft.The mechanical properties of turbodrill mainly depend on the hydraulic characteristics of turbine stator and rotor cascade,and the blade shape is one of the main factors that affect the hydraulic characteristics of turbine cascade.Now,the characteristics of the turbine blade profile are mainly focused on the feature of the cross section line and the feature of the space surface.However,all kinds of design methods of blade profile are complex and lack of unity.Therefore,it's so hard to compare the advantages and disadvantages.Most of the blades used on turbodrill are straight blades,and lack of research on the spatial profile.Therefore,it is of great significance to study the influence of the blade profile modeling method and the shape characteristics of the space blade on its hydraulic characteristics.In this paper,the blade of ?175 turbodrill used in the field of oil drilling is studied.Based on the parametric design of the blade line and the forming of the complex space blade,The influence of blade profile design parameters and space blade forming rule on hydraulic performance is analyzed by numerical simulation,respectively.The main research contents and results are as follows:(1)Taking the size parameters and performance parameters of turbo drilling tools as raw data,based on the unified design parameters and coordinate system,the mathematical expressions of different curve modeling methods are deduced respectively.And the advantages and disadvantages of different molding methods are analyzed comprehensively,Finally,a modeling method suitable for parametric design of turbine blade profile is determined.(2)The method for modeling the complex surfaces of different space blades is studied,and the analytical expressions of the relevant spatial blade stacking lines are deduced.By analyzing the influence of space blade design parameters on the blade shape,and using the actual parameters as an example to establish a related blade model,the feasibility of controlling the space blade shape by the stacking parameters was verified.(3)Combining VB and matlab mixed programming and VB's secondary development technology of Solid Works,An interactive software based on the parametric design of the blade profile and the single channel simulation model of the ?175 turbodrill is designed and developed,which lays a foundation for the simulation of the hydraulic performance of the blades under different space blade and parameters.(4)Based on the reference data,the validity of the numerical simulation is verified..The influence of the installation angle and front and back edge cone angle of the straight blade on the characteristic curve of the turbine is studied respectively.Based on the foundation of straight blade analysis,the turbine characteristic curve and efficiency increase rate under different bending forms,bending angle,inclination angle,twist form and twist angle are also carried out.The velocity and pressure distribution in the blade flow field are analyzed,and the optimum structural parameters are obtained,which provides a theoretical reference for the blade design and optimization of the turbodrill.