Fluid-Structure Coupling Simulation And Orthogonal Numerical Experiment Of Positive Displacement Motor

Nowadays,underground mineral resources,such as oil and natural gas,are the most used energy sources in the world,and also the energy sources that all countries is competing to seize,explore and exploit.Screw drilling tools are the drilling tools for exploring and mining these mineral resources.Not only that,screw drills are widely used in other drilling operations due to their excellent performance.Positive displacement motor(PDM),as the power component,is the most vulnerable component of a screw drill.The working conditions of the PDM,such as the viscosity of the working fluid,the differential pressure at the inlet and outlet,and the resistance torque,have a great influence on the safety of its' structure.Domestic and foreign scholars have studied the effects of these factors on the working characteristics of PDM and have achieved many important results.However,most of them use the single factor method to study,and did not study the relationship between these various factors affecting the working characteristics of the PDM.This paper selects the PDM as the research object.Firstly,three-dimensional fluidstructure coupling dynamic simulation is carried out under no-load and working conditions to verify the rationality of the model.Then,the orthogonal experiment was designed,in which the effects of working fluid viscosity,inlet and outlet pressure difference,resistance moment on the output power of the PDM were studied emphatically.Through the analysis of variance,the primary and secondary effects of these three factors were obtained,as well as the optimal working condition.And,we verified the optimal working condition.In summary,the research results can reflect the influence and the relationship of different factors on the PDM,and help to select the best working condition and achieve the best working efficiency.