Abstract: A multiple bypass turbofan engine includes a core Brayton Cycle gas generator with a fuel rich burning combustor and is provided with a variable supercharged bypass duct around the gas generator with a supercharging means in the supercharged bypass duct powered by a turbine not mechanically connected to the gas generator. The engine further includes a low pressure turbine driven forward fan upstream and forward of an aft fan and drivingly connected to a low pressure turbine by a low pressure shaft, the low pressure turbine being aft of and in serial flow communication with the core gas generator. A fan bypass duct is disposed radially outward of the core engine assembly and has first and second inlets disposed between the forward and aft fans. An inlet duct having an annular duct wall is disposed radially inward of the bypass duct and connects the second inlet to the bypass duct. A supercharger means for compressing air is drivingly connected to the low pressure turbine and is disposed in the inlet duct.

Abstract: An annular E-seal is installed in a retainer ring in such a way as to have limited degrees of freedom in the radial and axial directions while being retained in a groove of the retainer ring during component assembly and disassembly. The relative diameters of the retainer ring and the seal leg are such that installation or removal of the seal can only be accomplished by a deliberate tipping of the seal leg in such a way as to reduce its effective projected radial height. Thus, once installed, the seal is connected to and remains with one of the elements defining the gap to be sealed.