Abstract: A system and method of reducing noise caused by jet engines is provided. The method comprises the steps of using the afterburner to heat the exhaust gas flow while simultaneously reducing power to the core engine. Together these two operations reduce the pressure of the exhaust gas in the nozzle area while holding the exhaust gas velocity constant, which maintains engine thrust while decreasing engine noise. The method may be supplemented by altering the location of the afterburner flames to create an inverted exhaust velocity profile, thereby decreasing engine noise even further.

Abstract: A turbofan engine includes a variable area fan nozzle which effectively changes the physical area and geometry within a fan bypass flow path to manipulate the pressure ratio of the bypass flow with a multitude of bladders circumferentially located about a core cowl.

Abstract: A propulsion system and method includes an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle and ejecting an exhaust flow through an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle.

Abstract: A system and method of reducing noise caused by jet engines is provided. The method comprises the steps of using the afterburner to heat the exhaust gas flow while simultaneously reducing power to the core engine. Together these two operations reduce the pressure of the exhaust gas in the nozzle area while holding the exhaust gas velocity constant, which maintains engine thrust while decreasing engine noise. The method may be supplemented by altering the location of the afterburner flames to create an inverted exhaust velocity profile, thereby decreasing engine noise even further.

Abstract: A gas turbine engine system includes a first nozzle section associated with a gas turbine engine bypass passage and a second nozzle section that includes a plurality of positions relative to the first nozzle section. In at least one of the positions, there is a gap between the first nozzle section and the second nozzle section. A movable door between the first nozzle section and the second nozzle section selectively opens or closes the gap.

Abstract: A propulsion system and method includes an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle and ejecting an exhaust flow through an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle.

Abstract: A propulsion system and method includes an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle and ejecting an exhaust flow through an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle.

Abstract: A gas turbine engine system includes a first nozzle section associated with a gas turbine engine bypass passage and a second nozzle section that includes a plurality of positions relative to the first nozzle section. In at least one of the positions, there is a gap between the first nozzle section and the second nozzle section. A movable door between the first nozzle section and the second nozzle section selectively opens or closes the gap.

Abstract: A gas turbine engine system includes a first nozzle section associated with a gas turbine engine bypass passage and a second nozzle section that includes a plurality of positions relative to the first nozzle section. In at least one of the positions, there is a gap between the first nozzle section and the second nozzle section. A movable door between the first nozzle section and the second nozzle section selectively opens or closes the gap.

Abstract: A turbofan engine includes a variable area fan nozzle which effectively changes the physical area and geometry within a fan bypass flow path to manipulate the pressure ratio of the bypass flow with a multitude of bladders circumferentially located about a core cowl.

Abstract: A propulsion system and method includes an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle and ejecting an exhaust flow through an annular exhaust nozzle about an axis radially outboard of the annular cooling flow nozzle.

Abstract: A gas turbine engine system includes a first nozzle section associated with a gas turbine engine bypass passage and a second nozzle section that includes a plurality of positions relative to the first nozzle section. In at least one of the positions, there is a gap between the first nozzle section and the second nozzle section. A movable door between the first nozzle section and the second nozzle section selectively opens or closes the gap.

Abstract: An internal flow mixer is attached to the rearward end of a turbofan engine for inverting the engine fan and core streams. Rearwardly of the internal flow mixer is a multi-lobed exhaust nozzle which mixes ambient air with the gases flowing from the flow mixer. An ejector housing lined with acoustic absorption material receives the flow from the exhaust nozzle and discharges the thrust producing gases in noise abatement condition.