US Patent 11879343 Systems for controlling variable outlet guide vanes

A fan assembly includes a fan duct, an inlet fan, an outlet guide vane assembly, and a control system. The inlet fan includes fan blades adapted to rotate about a central axis to force fan exit air toward an aft end of the fan duct. The outlet guide vane assembly is located in the fan duct downstream of the inlet fan and is configured to adjust a direction of the fan exit air. The outlet guide vane assembly includes a plurality of guide vanes that extend radially relative to the central axis and are configured to rotate to a first vane-pitch angle. The control system is configured to rotate the guide vanes redirect the fan exit air, vary a pressure downstream of the fan inlet, minimize intake flow distortion experienced by the inlet fan, reduce inlet fan vibratory response and/or improve fan operability margins.