US Patent 7614210 Double bypass turbofan

A variable cycle turbofan engine includes first and second fans independently joined to respective turbines. A first bypass duct surrounds a core engine disposed in flow communication with the second fan. A second bypass duct surrounds the first bypass duct in flow communication with the first fan. A first exhaust nozzle is joined to both the core engine and first bypass duct. And, a second exhaust nozzle is joined to the second bypass duct.