3D Numerical Simulation of Turbulent Flow in Postpositional Bulb Tubular Pump

Abstract

The computational fluid dynamics(CFD) method is used to investigate the three-dimensional(3D) flow fields in a postpositional bulb tubular pump.In the numerical modeling,RNG k-e turbulence model and SIMPLE algorism are employed.The velocity distribution and pressure of vertical plane at BEP are analyzed,as well as the velocity of impeller outlet,guide-vane outlet and the tail of the bulb.The focus is on the static pressure distribution of blade pressure surface and suction surface as well as the relative velocity distribution near the airfoil cross-sections under different conditions(the designed condition,large and small flow rates conditions).The hydraulic losses of various components of tubular pump are also calculated,and it is found that the guide vane and bulb unit occupy major share in hydraulic losses.The comparison between the mathematical model calculation result and the model-tested pump performance data shows that the calculation result agrees well with the test data in nearby the high efficiency area;however,deviation exists between them under large flow and small flow working conditions.Using CFD method to simulate the internal flow field of tubular pump can provide the basis for further design optimization of the tubular pump.