Flade discharge in 2-D exhaust nozzle

An aircraft gas turbine engine comprising:

• a fan section,
• at least one row of FLADE fan blades disposed radially outwardly of and drivingly connected to a fan in the fan section,
• a core engine downstream of the fan section, the core engine including a high pressure compressor, a combustor, and a high pressure turbine,
• a low pressure turbine downstream of the core engine and a transition section downstream of the low pressure turbine,
• the row of FLADE fan blades radially extending across a FLADE duct circumscribing the fan section,
• an engine inlet including a fan inlet to the fan section and an annular FLADE inlet to the FLADE duct,
• the transition section operable for converting axisymmetric gas flow from the low pressure turbine to two-dimensional gas flow for a two-dimensional exhaust nozzle,
• an afterburner disposed in an engine exhaust duct between the low pressure turbine and the transition section, a two dimensional flow FLADE air discharge fluid passage in fluid flow communication with the FLADE duct,
• a FLADE air discharge system including FLADE air upstream and downstream discharge slots in a divergent flap of the two dimensional exhaust nozzle and in fluid flow communication with the two dimensional flow FLADE air discharge fluid passage, and
• a valve for opening and closing the upstream and downstream discharge slots wherein the valve is operable for fully closing the upstream slot when the downstream slot is fully opened and fully opening the upstream slot when the downstream slot is fully closed.

An aircraft gas turbine engine comprising:

• a fan section,
• at least one row of FLADE fan blades disposed radially outwardly of and drivingly connected to a fan in the fan section, a core engine downstream of the fan section,
• the core engine including a high pressure compressor, a combustor, and a high pressure turbine, a low pressure turbine downstream of the core engine and a transition section downstream of the low pressure turbine,
• the row of FLADE fan blades radially extending across a FLADE duct circumscribing the fan section, an engine inlet including a fan inlet to the fan section and an annular FLADE inlet to the FLADE duct,
• the transition section operable for converting axisymmetric gas flow from the low pressure turbine to two-dimensional gas flow for a two-dimensional single expansion ramp exhaust nozzle,
• the single expansion ramp exhaust nozzle including convergent and divergent sections and a variable area throat therebetween,
• an afterburner disposed in an engine exhaust duct between the low pressure turbine and the transition section,
• a two dimensional flow FLADE air discharge fluid passage in fluid flow communication with the FLADE duct,
• a FLADE air discharge system including FLADE air upstream and downstream discharge slots in a lower divergent flap of the divergent section and in fluid flow communication with the two dimensional flow FLADE air discharge fluid passage, and
• a valve for opening and closing the upstream and downstream discharge slots wherein the valve is operable for fully closing the upstream slot when the downstream slot is fully opened and fully opening the upstream slot when the downstream slot is fully closed.

A method of operating an aircraft gas turbine engine comprising:

• operating the engine to rotate a fan section and at least one row of FLADE fan blades disposed radially outwardly of and drivingly connected to a fan in the fan section,
• directing FLADE airflow from a FLADE duct circumscribing the fan section wherein the row of FLADE fan blades radially extend across the FLADE duct to a two dimensional flow FLADE air discharge fluid passage in fluid flow communication with the FLADE duct, and
• opening and closing FLADE air upstream and downstream discharge slots in fluid flow communication with the two dimensional flow FLADE air discharge fluid passage and disposed in a divergent flap of a two dimensional nozzle, and
• fully closing the upstream slot when the downstream slot is fully opened and fully opening the upstream slot when the downstream slot is fully closed.