A Numerical Simulation of 3DUnsteady Flow in Roto?jet Pumps by Dynamic Mesh Technique

By using 3Ddynamic mesh technique,the numerical simulation of the unsteady flow field in a roto-jet pump was performed in this work.The surface motion of the impeller computational domain was defined by the profile file in fluent commercial code,in which the rotational direction and speed of the impeller were specified.In the simulation by means of dynamic mesh technique,all the computational domains,as stationary,were set in an inertial reference frame.Three methods(spring-based smoothing,dynamic layering and local remeshing)were used to achieve mesh deformation.The time-dependent relations of velocity field,pressure,the outlet flow rate and the radial force were obtained by this unsteady simulation.After a startup stage the flow starts to exhibit time-periodic behavior corresponding to blade passing frequency of impeller.Radial force direction from the axis points to the back of the pick?up pipe.This work shows that dynamic mesh technique can achieve numerical simulation of three-dimensional unsteady flow field in roto-jet pump and have a strong versatility and broad application prospects.