Analysis Of Influence Of Related Parameters Of Single-Head Screw Motor On Output Power Based On Fluid-Structure Coupling

Screw motors are widely used in drilling operations in geological exploration,oil drilling,construction pipeline construction and defense engineering.The contact friction between the rotor and the stator of the screw motor and the leakage of the liquid affect the output power of the motor,thereby affecting the drilling capability of the entire screw drilling tool.At present,most of the engineering only calculates the motor efficiency from the empirical formula,and does not take into account the contact state between the rotor and the stator and the liquid motion state in the motor.This calculation method has errors and cannot be sufficiently close to the actual working condition for the output of the screw motor.The power is accurately calculated.Starting from the working principle and design theory of screw motor,the nonlinear model of screw motor contact is established under the condition of initial flow,and the nonlinear contact dynamics simulation analysis of the motor without drilling fluid is carried out.The set of working conditions under the surplus and the pitch are analyzed to obtain the optimal structural parameters of the motor.The solid structure of the screw motor is immersed in the drilling fluid of the wellbore,and the fluid-solid coupling calculation model of the screw motor is established.The immersion boundary method and the fluid-solid coupling domain method are used to solve the problem.Under the premise of the motor pitch,by changing the parameters such as interference and motor flow,the results of motor pressure drop,motor equivalent stress,contact pressure,frictional resistance torque and torque transmission efficiency under different working conditions are obtained.The output power of the screw motor.The comparison results show that the motor output power increases first and then decreases with the increase of the interference,and reaches the peak at the interference of 0.5mm.The peak value is 22.08 kW.The motor performance under this interference is the best.The flow effect law of the best performance motor is studied.The result is that in the interval of 13L/s-17L/s,the increase of motor flow causes the motor pressure drop to increase,and the torque transmission efficiency of the motor follows.When reduced,the output power increases.This study can provide theoretical basis and new ideas for the accurate calculation of the output power of the screw motor.