Numerical Simulation And PIV Experimental Research On Unsteady Flow In Eccentric Annulus

The flow law in the eccentric annulus with inner cylinder reciprocating axially of the produced fluid in the polymer flooding wells is studied in this paper. It's that the study has a significant engineering meaning in the optimizing of the parameters of the pumping unit and in the prevention of the eccentric wear of the sucker rod. Whereas the flow of the produced fluid by means of the polymer flooding wells is the flow of Non-newtonian fluid in eccectric annulus with inner cylinder reciprocating axially. Relative to the steady flow, unsteady flow still exist many difficulties no matter whether in theoretical research, experimental study or numerical calculation research in the field, and it become the most challenging one of the hot topic of hydrodynamics reaserch.In view of the subject of the study in this paper, firstly, the physical models of concentric and eccentric annulus are set up in three dimensional Cartesian coordinate system by using PHOENICS software, in the process of numerical simulation, finite volume method is used to discretise the governing equantions and the simplest algorithm is employed to solve the disctretised equations, the k-εcalculating turbulence model is used and the method of wall functions is used near wall, dual-time-step implicit iterative forward method is used for time-discrete, the numerical simulation calculation of annular flow field is carried out. Through post-processing of the data by using tecplot, sci and origin software, the distribution of the velocity of unsteady flow in eccentric annulus with inner cylinder reciprocating axially is obtained at different times and nuder different conditions, and then the effects of stroke and the frequency of completing two strokes per minute, fluid viscosity and eccentricity on the axial velocity are analyzed in detail. Secondly, in order to verify the correctness of the numerical solution, this paper develope experimental study on the unsteady flow of power law fluid in eccentric annulus with PIV Technology, and establish a set of device of vertical annulus pipeline that the eccentricity was adjustable. The numerical simulation result is basically accord with the PIV experimental result, it turns out that the numerical simulation of annular flow field by PHOENICS is viable.This paper proves the feasibility of combining numerical simulation with PIV technology for the research of helical turbulent flow of power law fluid in eccentric annulus, the view is proposed innovately, laid the foundation for unsteady flow for future research. The experimental results of this paper will be of certain reference value to theory research and field application.