Three-dimensional inverse design and hydrodynamic performance analysis of contra-rotating axial flow pump

In order to explore the contra-rotating axial flow pump design method and analysis its hydrodynamic performance, the inlet and outlet velocity triangle of front rotor and rear rotor was analysed, then, a high specific speed contra-rotating axial flow pump was designed using three dimensional method based on the condition of the front rotor outlet circulation equal to the inlet circulation of the rear rotor. At last, the performance of the pump is calculated by using RANS simulation. The results show that: the efficiency of the pump reaches 80.2% on the mass flow design point, namely, the average efficiency of the front rotor and rear rotor is up to 89%. At the same time, the efficiency will decrease rapidly when the mass flow is greater than the design flow. The efficiency of contra-rotating axial flow pump can be maintain higher than 80% by changing the rear rotor speed when the mass flow is in the range of 0.68 Q(d) similar to 1.07 Q(d), which verifies changing rear rotor speed can effectively expand the operation range of pump's high efficiency.