Structure Design And Fluid Structure Interaction Simulation Analysis Of Internal Meshing Cycloidal Pump

At present,in the aspect of numerical simulation of Cycloidal pump,most of the researches are based on CFD?Computational Fluid Dynamics?to analyze the pump under different operating conditions?such as speed,temperature,etc.?,and few people have studied the characteristics of pump under FSI?fluid structure interaction?.Firstly,based on COMSOL,the model of cycloidal pump is established.The dynamic grid technology is used in the rotating domain,and the fluid structure coupling interface is set up.After setting the corresponding boundary conditions,CFD and FSI simulation are carried out for the pump,and the results are compared with the experiment results and the feasibility of the simulation model is verified by experiments.It is found that the simulation results after coupling are closer to reality,and FSI simulation results are more accurate.Further,based on the FSI simulation,the cross-sectional and longitudinal flow of the Cycloidal pump's rotating region and the oil inlet and outlet chambers are analyzed.Finally,based on the analysis results of FSI,the structure of the Cycloidal pump is optimized,and the performance of the optimized and non optimized Cycloidal pump is compared at different rotating speeds.The results show that:1)By comparing the results of CFD,FSI and experiment,the feasibility of the simulation model is verified,and the simulation results of FSI are closer to the reality;2)Furthermore,by comparing the velocity and pressure of a certain section in the fluid field between the inner and outer rotors,it is concluded that:the obtained pressure CFD is more than FSI,and the calculated velocity CFD is less than FSI;the fluctuation value of CFD pressure with time at a certain point of the coupling interface between the inner and outer rotors and the fluid is greater than that of FSI,and the fluctuation value of CFD pressure with time is larger than that of the maximum pressure distribution of CFD and FSI at different temperatures the pressure of FSI fluctuates with time.3)Through the analysis of the rotating region,it can be concluded that the negative pressure generated by A₀?A₂ is larger than that generated by A₃?A₅ in the oil absorption stage of closed region a,and the positive pressure generated by A₆?A₈ is lower than that generated by A₉?A₁₁ in the oil discharge stage of closed region A.4)Through the analysis of the oil inlet cavity,it can be concluded that in the region of-18 mm<x<-5 mm,Z<-8 mm,the oil absorption capacity is low due to the low negative pressure,and the liquid appears transverse.Through the analysis of the oil discharge chamber,it can be concluded that the oil flow from the left high pressure area to the right low pressure area in the Z<-8 mm area is transverse,which hinders the oil flow from the right low pressure area to the oil pipe,resulting in the decrease of the outlet flow.5)The oil inlet and outlet cavities of the cycloid pump are optimized,and the performance of the cycloid pump before and after optimization is compared under different rotating speeds.At 1500 r/min,the flow pressure characteristics of the optimized cycloid pump are improved;at 3000 r/min,the flow characteristics of the optimized cycloid pump are improved.Through the structural design of cycloid pump,comparing the different research methods of cycloid pump,using more practical FSI analysis method to analyze cycloid pump,and optimize the design of cycloid pump,finally forming a set of cycloid pump structural design and analysis method,providing reference for the analysis and design of other fluid machinery.