A gas turbine engine exhaust nozzle comprises a housing having an aft end that terminates in a row of chevrons. At least one surface of the housing has scalloped root regions proximate bases of adjacent chevrons. The scalloped root regions have a reduced thickness relative to the rest of the aft end.

A gas turbine engine exhaust nozzle comprises a housing having an aft end that terminates in a row of chevrons. At least one surface of the housing has scalloped root regions proximate bases of adjacent chevrons. The scalloped root regions have a reduced thickness relative to the rest of the aft end.

The present invention discloses an unmanned helicopter, and belongs to the technical field of unmanned aerial vehicles. The unmanned helicopter includes an air inlet system, an exhaust system, a cooling system and a dynamic balance system. The air inlet system is fixed on a second side; the exhaust system is fixed on a third side; and the cooling system is fixed on a first side, and the dynamic balance system is fixed on a tail. The airflow at the outside of the unmanned helicopter flows into the air inlet system smoothly, quickly and efficiently under the action of its own flow velocity relative to the unmanned helicopter, therefore the technical problem in the prior art that the air entering the fuselage with a unit volume is burnt insufficiently, which generates adverse effects on the normal flight of the unmanned helicopter, is solved.

An acoustic panel structure includes a perforated front sheet, a back sheet and a porous core between the front sheet and the back sheet. The acoustic panel structure also includes a non-perforated back cover which overlaps a portion of the back sheet. A portion of the back sheet is perforated and another portion of the back sheet is not perforated. An acoustic chamber is formed at least in part by the space between the back sheet and the back cover. The acoustic chamber may also be formed in part by the space between the front sheet and back cover. The space between the back sheet and the back cover is generally elongated in the x-y direction of the acoustic panel structure. This relatively thin acoustic panel structure is configured to attenuate long wavelength and low frequency noise.

A structural panel for an aircraft nacelle may comprise a core between a perforated skin and a septum. A plurality of dividing walls may extend between the septum and a backskin to define a plurality of cavities. Each cavity may be in fluid communication with a plurality of cells in the core through the septum. The cells and the cavities may attenuate noise.

A pylon is provided for connecting a propulsion system to an aircraft. The pylon includes a structure configured to structurally tie the propulsion system to the aircraft. The pylon also includes a pylon fairing configured to house and provide an aerodynamic cover for the structure. A lower aft fairing segment of the pylon fairing includes a plurality of apertures. The apertures are fluidly coupled with a sealed, sound attenuating chamber within the pylon.

Provided is a gas turbine system including: a compressor that compresses external air to generate compressed air; a combustor that burns the compressed air generated by the compressor together with fuel to generate a combustion gas; a turbine driven by the combustion gas generated by the combustor; an exhaust unit that guides a combustion gas that has passed through the turbine to outside; a nacelle formed in a cylindrical shape and extending along an axis line about which the turbine rotates and arranged so as to cover the compressor, the combustor, the turbine, and the exhaust unit; and an exit unit that guides the combustion gas, which passed through the turbine, to a discharge port provided in the surface of the nacelle.

Provided is a gas turbine system including: a compressor that compresses external air to generate compressed air; a combustor that burns the compressed air generated by the compressor together with fuel to generate a combustion gas; a turbine driven by the combustion gas generated by the combustor; an exhaust unit that guides a combustion gas that has passed through the turbine to outside; a nacelle formed in a cylindrical shape and extending along an axis line about which the turbine rotates and arranged so as to cover the compressor, the combustor, the turbine, and the exhaust unit; and an exit unit that guides the combustion gas, which passed through the turbine, to a discharge port provided in the surface of the nacelle.

A jet noise suppressor including a nozzle having a front end and an opposed rear end, spokes extending radially inward from the nozzle, the spokes defining vents, and a center-body connected to the spokes and in fluid communication with the vents, the center-body being positioned centrally within the nozzle and including a closed front end and an open rear end, wherein the front end of the nozzle entrains a first ambient airflow passing through the nozzle and exiting the rear end of the nozzle proximate a periphery of the nozzle, and wherein the vents entrain a second ambient airflow passing through the center-body and exiting the rear end of the nozzle proximate a center of the nozzle.

A jet noise suppressor including a nozzle having a front end and an opposed rear end, spokes extending radially inward from the nozzle, the spokes defining vents, and a center-body connected to the spokes and in fluid communication with the vents, the center-body being positioned centrally within the nozzle and including a closed front end and an open rear end, wherein the front end of the nozzle entrains a first ambient airflow passing through the nozzle and exiting the rear end of the nozzle proximate a periphery of the nozzle, and wherein the vents entrain a second ambient airflow passing through the center-body and exiting the rear end of the nozzle proximate a center of the nozzle.