Influence of suction chamber profile on flow field of annular jet pump

Abstract

Jet pump is a kind of fluid machinery, which uses jet shear and turbulent diffusion to transfer mass and energy. It is widely used in water project, civil engineering and other fields. In order to investigate the influence of suction chamber profile on flow field of annular jet pump, the conical suction chamber and the streamlined suction chamber were compared by applying turbulence numerical simulation method. The performance, pressure characteristics, velocity and turbulent energy distributions of annular jet pumps with two suction chambers are analysed. The calculation shows that compared with the traditional conical suction chamber, the efficiency of annular jet pump with streamlined suction chamber is improved at low flow ratio, and the change is not obvious at high flow ratio. In the same section, the cross sectional area of streamlined suction chamber is slightly larger than that of conical suction chamber, so the primary flow velocity near the wall is slightly lower, which can reduce the friction loss caused by high speed wall-attached flow. In addition, the smooth turning of the primary flow in streamlined suction chamber can weaken the extrusion on the entrained flow field. Different from the conical suction chamber, the streamlined suction chamber is smoothly connected with throat without sudden corner change, which can eliminate the low pressure near the inlet wall of throat, improve the wall pressure distribution and reduce the possible cavitation. The research results of suction chamber profile of annular jet pump can provide scientific basis for the popularization and application of jet pump.