Patent ID: 6901739
Filing Date: 2005-06-07
Classification: F01D,F02K

Abstract:
1. A multiple bypass turbofan gas turbine engine comprising: axially spaced-apart first and second stage fans of the engine fan connected in driving engagement to a low pressure shaft; a fan bypass duct circumscribing the second stage fan; a first bypass inlet to the fan bypass duct disposed axially between the first and second stage fans; a second bypass inlet to the fan bypass duct axially disposed between the second stage fan and an annular core engine inlet; first stage fan blades of the first stage fan disposed axially across a first fan duct and second stage fan blades radially disposed axially across a second fan duct; the second fan duct located axially aft of the first bypass inlet and disposed radially inwardly of the fan bypass duct; a fan shroud dividing the second stage fan blades into radially inner and outer fan hub and tip sections, respectively; the tip sections radially disposed in a fan tip duct including an annular duct wall having a non-rotatable forward duct wall portion adjacently forward of the rotatable fan shroud; and an axially translatable deflector positioned to close the fan tip duct when it opens the first bypass inlet and open the fan tip duct when it closes the first bypass inlet.