US Patent 11852037 Rim driven thruster with adjustable rotor blade pitch

A flow control system, such as a thruster, includes an annular rotor within an annular housing. The annular rotor rotates about a central axis relative to the annular housing. The flow control system includes rotor blades with respective bases that are coupled to the annular rotor, and with respective tips directed toward the central axis. The flow control system includes a first actuator that rotates the annular rotor about the central axis relative to the annular housing, thus also rotating the rotor blades about the central axis relative to the annular housing. The flow control system includes a second actuator that rotates the rotor blades relative to the annular rotor. Actuation of the second actuator rotates a rotor blade about a rotor blade axis that extends from a base of the rotor blade toward the central axis.