The pump includes a first rotatable member including a radially inward facing groove having an edge. The first rotatable member configured to receive a plurality of flows of fluid over the edge. The first rotatable member configured to rotate at a first angular velocity. The pump also includes a second rotatable member including a collector configured to rotate at a second angular velocity. The second rotatable member also includes a plurality of scoop tubes extending radially outwardly from the collector. Each scoop tube of the plurality of scoop tubes includes a first end coupled in flow communication to the collector and a second end including an inlet opening extending into the groove. The second end curved such that the inlet opening is open in a direction of rotation of the second rotatable member. The inlet opening configured to scoop a fluid collected in the groove.