The adoption of the contra-rotating rotor has been proposed in response to a demand for the axial flow pump with higher specific speed. The internal flow field and blade rows interactions between the front and rear rotors should be considered in the design for higher performance and more stable operation, but has not been clarified yet. The flow field in contra-rotating axial flow pump was measured at various flow rates with the LDV and wall pressure measurements. In the present paper, the experimental and numerical results in the flow field between front and rear rotors are shown at the design flow rate and the flow behaviors are discussed, related on blade loading, blade tip leakage flow, wake and blade rows interaction.
