Rotating detonation augmentors with flow restriction control for gas turbine engines

A gas turbine engine comprising:

• a bypass duct having an outer wall arranged circumferentially about an axis to define an outer boundary of a flow path of air and an inner wall arranged circumferentially about the axis to define an inner boundary of the flow path,
• a fan configured to rotate about the axis and push the air through the bypass duct,
• a rotating detonation augmentor located in the bypass duct and configured to define a first throat and produce a rotating detonation wave downstream of the throat, the rotating detonation augmentor including a first augmentor band that extends circumferentially about the axis, the first augmentor band is spaced apart radially from the outer wall and the inner wall of the bypass duct and configured to receive a first portion of the air from the fan and to inject fuel into the bypass duct and detonate the fuel and the first portion of the air received from the fan, and
• a flow valve movable relative to the first augmentor band of the rotating detonation augmentor, the outer wall, and the inner wall between a first position in which a gap between the flow valve and the first augmentor band has a first size to decrease a cross-sectional flow area for the air in the bypass duct at a location axially aligned with the first augmentor band of the rotating detonation augmentor and a second position in which the gap between the flow valve and the first augmentor band has a second size that is greater than the first size to increase a cross-sectional flow area for the air in the bypass duct at the location axially aligned with the first augmentor band of the rotating detonation augmentor.

A method comprising:

• directing a flow of air being pushed by a fan of a gas turbine engine between a first wall and a second wall of a bypass duct that is arranged along an axis and circumferentially around the fan,
• detonating fuel and a portion of the air received from the fan with a rotating detonation augmentor located in the bypass duct, the rotating detonation augmentor includes a first augmentor band that extends circumferentially around the axis, and the first augmentor band being spaced apart from the first wall and the second wall,
• moving a flow valve relative to the first wall of the bypass duct, the second wall of the bypass duct, and the first augmentor band to a first position in which a gap located axially between the flow valve and the first augmentor band has a first dimension prior to detonating the fuel and the portion of the air received from the fan with the rotating detonation augmentor, and
• moving the flow valve relative to the first wall of the bypass duct, the second wall of the bypass duct, and the first augmentor band to a second position in which the gap between the flow valve and the first augmentor has a second dimension that is greater than the first dimension in response to stopping operation of the rotating detonation augmentor.