US 12,146,413 B1
Circumferentially variable flow control in fan outlet guide vane assemblies for distortion management and stall margin in gas turbine engines
Robert W. Heeter, Indianapolis, IN (US); William B. Bryan, Indianapolis, IN (US); Daniel E. Molnar, Jr., Indianapolis, IN (US); and Gregory J. Hebert, Indianapolis, IN (US)
Assigned to Rolls-Royce North American Technologies Inc., Indianapolis, IN (US)
Filed by Rolls-Royce North American Technologies Inc., Indianapolis, IN (US)
Filed on Dec. 12, 2023, as Appl. No. 18/537,071.
Int. Cl. F01D 17/10 (2006.01); F01D 17/16 (2006.01)
CPC F01D 17/105 (2013.01) [F01D 17/162 (2013.01); F05D 2220/32 (2013.01); F05D 2230/60 (2013.01); F05D 2240/128 (2013.01); F05D 2260/606 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A fan duct assembly adapted for use with a gas turbine engine, the fan duct assembly comprising:
a bypass duct arranged circumferentially around a central axis, the bypass duct having an outer wall that defines a radially outer boundary of a gas path of bypass air conducted through the fan duct assembly and an inner wall that defines a radially inner boundary of the gas path,
a fan comprising a plurality of fan blades that extend radially outward relative to the central axis and configured to rotate about the central axis to force the bypass air through the gas path,
an outlet guide vane assembly coupled with the bypass duct axially downstream of the fan and having a plurality of vanes configured to adjust a direction of the bypass air received from the plurality of fan blades, the plurality of vanes including a first plurality of vanes that extend radially between the inner wall and the outer wall of the bypass duct and a second plurality of vanes circumferentially spaced apart from the first plurality of vanes and extending radially between the inner wall and the outer wall of the bypass duct, and
a circumferentially variable flow control system configured to direct selectively a portion of the bypass air flowing through the gas path at a location aft of the plurality of vanes radially into each of the first plurality of vanes and each of the second plurality of vanes to minimize stall at the plurality of vanes,
wherein, in a first mode, the circumferentially variable flow control system directs the portion of the bypass air into each of the first plurality of vanes without directing the portion of the bypass air into each of the second plurality of vanes and, in a second mode, the circumferentially variable flow control system directs the portion of the bypass air radially into each of the second plurality of vanes without directing the portion of the bypass air into each of the first plurality of vanes.