Design and Performance Analysis of Contra-rotating Pumpjet Propulsor under Condition of Torque Unbalance

In order to balance the torque of front rotor and rear rotor of underwater vehicle, the analysis of the speed triangles at the inlet and outlet of the front and rear rotor has been done. Then, the thought of using contra-rotating pumpjet to achieve the objective was raised. The stator is installed behind the rear rotor so as to ensure the overall torque of the propulsor balance, at the same time, the stator can also support the shroud of the propulsor. the parameter design of the rotor and the stator has been carried out by using the three dimensional inverse design method. At last, the performance of the designed pumpjet propulsor is obtained when it is installed on the underwater vehicle By using computational fluid dynamics. The results show that the total torque of the propulsor is reduced to 1.8 N * m on the design point although the power difference ratio of the front rotor and the rear rotor is 20%. The torque ratio is also reduced from 4.6% to 0.4%, which is good to meet the propulsor balance requirement and verifies the 3-D design method of pumpjet is effective