PIV experimental study on the flow field in the rotor zone of an annular centrifugal contactor

•We measured the flow field in the rotor of ACC with PIV technique.•Flow field with different rotational speed and flow rate were tested.•The rotational speed had a significantly impact on the velocity.•The flow rate had less effect on the tangential velocity and radial velocity.•Vortexes formed in the rotational reference frame demonstrated CFD simulations. In this study, particle image velocimetry (PIV) technique was employed to measure the flow field in the rotor zone of an annular centrifugal contactor (ACC). The velocity distribution and streamline diagrams of the flow field relative to the stationary reference and rotating reference frame was investigated as well. It was found that the fluid formed a vortex in each separation cell relative to the rotating reference frame. The magnitude of the tangential velocity and that of radial velocity significantly changed with the speed of rotation. The flow rate had insignificant impact on the tangential velocity and the radial velocity.