Patent attributes
A subsea fluid pressure-increasing machine includes an elongated member that is rotatable about a longitudinal axis. The machine also may include a plurality of impellers each having a leading edge, a trailing edge, a suction side, and a chord line defined by a line between the leading and trailing edges. Each impeller is fixedly mounted to the member such that a chord angle defined by an angle between the chord line and the rotation direction is less than or equal to a stall angle at which a maximum force is exerted on a fluid in a direction primarily parallel to the longitudinal axis when the member is rotated in the rotation direction. At least some of the impellers comprise one or more features that effectively reduce a pressure peak or specific loading of the suction side such that the axial length of the impeller is configured to be reduced without exceeding a desired specific load.
