Small Size Medium And High Speed Impeller Mechanical Hydraulic Performance Numerical Simulation Analysis

Impeller machinery,as a kind of rotating machinery,widely used in various industries and even in the national economy and plays an irreplaceable important role,the impeller machine widely used in petroleum industry,water conservancy,chemical industry,power engineering,aerospace and other fields.With the further development of various fields continuously,mechanical product performance,reliability,development of impeller and periodic and equipment matching with environment continuously put forward new and higher requirements.On the basis of fluid energy transfer in a different direction,such as mechanical impeller can be divided into mechanical power(prime mover)and conveying machinery(machine).Blade is the key to the impeller mechanical components,can influence on the performance of the impeller mechanical work completely and transformation efficiency,leaf type and key factors of the blade,different profile equation has a completely different performance.Therefore to study the hydraulic performance of impeller machinery,this thesis will be the most common form of downhole drilling tools in the oil field-turbodrill research as the breakthrough point.Turbodrill since the 1980s,as one of the three important technology in petroleum engineering,its structure compared with rotary drilling with screw drill tool,etc.,degree of widely used,the advantage of already received important attention in the field of drilling engineering.But as a result of turbodrill speed is too high,can match with the bit of wear and tear"is poorer,makes the application of the turbodrill is limited to a certain extent.In recent years,as slim-hole,small hole and other international high-end the development of drilling technology,meanwhile can withstand the high speed,low wob all kinds of new type of bit of the success of research and development and has been well used,the advantage of the turbodrill reflected once again.It is worth noting that the slimhole,tiny hole wellbore radial size is small,the turbine stator design and performance of the proposed new challenges.This paper firstly studies the characteristics of the turbine parameters effect on turbine performance and efficiency.Start from the working characteristic of conventional turbodrill,analysis of the characteristic parameters affect the performance of the turbine,can for the turbine to further improving the efficiency of conversion from the turbine torque and provide basis for optimization design.In drilling fluid flowing through the turbine rotor as the research object,with the impeller rotating machinery for a yuan the basis of euler equation,and make the three basic assumptions.Discusses the transformation of the turbine torque characteristic,power characteristics,effective pressure the change of the primary parameters affect the performance of the turbine;Through the drilling of turbodrill besides doing useful work,and part of the drilling fluid loss in the form of energy loss,so drilling fluid are discussed in the form of energy loss.The geometric structure of turbine blade cascade is studied parameters affect the performance of the turbine.Starting from the theoretical model of turbine blade movement,the drilling fluid flowing through the turbine in flow channel of the basic motion law,determine the drilling fluid outlet velocity of the stator and rotor speed,rotor speed,stator import export.Can be used as standard and appraisal of turbine power,torque working characteristic parameters,such as three turbine dimensionless coefficient.Because each coefficient collocation of combination can form a certain turbine cascade structure,so it needs to determine the geometry parameters of turbine.Analyses the common method to curve modelling,choose five times polynomial in the modelling design,3 d model of turbine blade.The commonly used CFD method is verified by numerical simulation.Turbine was established by applying the finite element simulation software Fluent,the flow model and grid model,as the external conditions such as design of the traffic simulation.Validate the designed hydraulic performance of turbine.At the same time,studied the turbine rotor structure change influence on the working performance of the turbine,the rotor grid is designed three different structure of the turbine.Based on the working state of liquid flows through the stator velocity triangle theory analysis,and the energy loss caused by the radial clearance and reflectance outer disc friction loss caused by qualitative study,quantitative analysis using numerical simulation.The research results show that(1)think that when the structure size of the turbine and the drilling fluid flow is constant value,the turbine torque and rotational speed of a linear relationship,and with the increase of rotational speed,the transformation of the turbine torque linear decrease;Turbine power characteristic curve of a quadratic function relation with the rotational speed,and reached the maximum when the speed of the turbine,the torque is equal to zero,the power is zero,when the speed of the turbine maximum speed in general,the turbine will be the biggest power;Effective pressure head and the speed of the turbine turbine and a quadratic function relation;For drilling fluid flowing through the turbine rotor as the research object,the three kinds of energy loss of drilling fluid,the hydraulic loss of the impact of energy loss in the loss of the main factors,therefore should ensure that as far as possible in the design of drilling fluid into the direction of the turbine blade cascade close to the structure of the blade Angle;(2)applied five times polynomial for small size high speed turbine design is reasonable,the design of the turbine around the best job in the speed of 4200 r/min,efficiency up to 45.46%;(3)3 different rotor grid structure of the turbine is calculated,according to the results of that turbine stator radial clearance,the existence of the outer ring distribution are the influence factors of the turbine,and argues that the disc friction loss is caused by outer ring distribution in turbine rotor output performance and energy loss of the important factors.By analyzing the structure of three kinds of turbine,think its best efficiency point corresponding work speed,output torque and hydraulic efficiency are not the same,and?type turbine with?type turbine is smaller than?type turbine best working speed;?type turbine torque,the largest of?type turbine times,minimum?type turbine,the Mi_?>Mi_?>Mi_?;And?type hydraulic efficiency of turbine,the largest?type turbine times,minimum?type turbine hydraulic efficiency,namely the?_?>?_?>?_?.