摘要:
An axial flow positive displacement engine has an inlet axially spaced apart and upstream from an outlet. Inner and outer bodies have offset inner and outer axes extend from the inlet to the outlet through first, second, and third sections of a core assembly in serial downstream flow relationship. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes respectively. The inner and outer helical blades extend radially outwardly and inwardly respectively and have first, second, and third twist slopes in the first, second, and third sections respectively. The first twist slopes are less than the second twist slopes and the third twist slopes are less than the second twist slopes. A combustion section extends axially downstream from the second section through at least a portion of the third section.
摘要:
A gas turbine engine is disclosed having a fan system with a front stage fan rotor and an aft fan rotor coupled to a low-pressure turbine, a core having a compressor coupled to a high-pressure turbine, an annular inner bypass passage and an annular outer bypass passage. The aft fan rotor has a row of aft fan blades having an arcuate splitter that forms a portion of an inner flow passage and an outer flow passage wherein the aft fan blade pressurizes an inner flow and an outer flow and wherein the fan tip pressure ratio can be changed while the air flow into the front stage fan rotor is held substantially constant.
摘要:
An adaptive gas turbine engine is disclosed having a convertible fan system adapted to have a variable fan pressure ratio while the air flow into the convertible fan system remains substantially constant and an adaptive core having a compressor capable of maintaining a substantially constant core pressure ratio while a core airflow flow rate is varied.
摘要:
An inlet apparatus for a gas turbine engine includes: a fan duct adapted to surround at least one row of rotating fan blades, the fan duct having a circular frontal area, and defining a first inlet plane; and an outer duct surrounding the fan duct, the outer duct including: a first frontal area shape at the first inlet plane which defines, cooperatively with an exterior of the fan duct, at least one lobe through which air can pass; and a second frontal area shape at a second inlet plane located axially downstream from the forward end which is circular, and which defines, cooperatively with an exterior of the fan duct, an annulus through which air can pass.
摘要:
A convertible fan system is disclosed having a fan rotor with a plurality of fan blades having an arcuate splitter that forms a portion of an inner flow passage and an outer flow passage wherein an inner portion of the fan blade pressurizes an inner flow in the inner flow passage and an outer portion of the fan blade pressurizes an outer flow in the outer flow passage and a vane system having an outer vane that is adapted to be able to vary the flow in the outer flow passage such that pressure ratio of the fan system can be varied.
摘要:
A method of operating a compressor in an adaptive core engine is disclosed. The method comprises the steps of operating a front block compressor to increase pressure of a fluid to a first pressure ratio in a high-power mode operation; operating a rear block compressor coupled to the front block compressor such that the front block compressor and the rear block compressor operate at the same physical speed; closing a rear block stator vane located axially forward from the rear block compressor such that the flow of the fluid into the rear block compressor is substantially cut off; and keeping a blocker door opened such that substantially all of the fluid pressurized by the front block compressor flows through a bypass passage during the high-power mode operation. The operation may be transitioned from the high-power mode to a low-power mode by opening a rear block stator such that the rear block compressor receives at least a portion of the fluid flowing from the front block compressor and maintains an overall engine pressure ratio.
摘要:
An inlet apparatus for a gas turbine engine includes: a fan duct adapted to surround at least one row of rotating fan blades, the fan duct having a circular frontal area, and defining a first inlet plane; and an outer duct surrounding the fan duct, the outer duct including: a first frontal area shape at the first inlet plane which defines, cooperatively with an exterior of the fan duct, at least one lobe through which air can pass; and a second frontal area shape at a second inlet plane located axially downstream from the forward end which is circular, and which defines, cooperatively with an exterior of the fan duct, an annulus through which air can pass.
摘要:
A method of operating a gas turbine engine is disclosed having the steps of directing a flow of air to a front fan stage at a selected fan flow rate, fan speed and front fan stage pressure ratio corresponding to a selected first operating power level, pressurizing a portion of the flow from the front fan stage in a aft fan rotor to a first tip pressure ratio to generate a first overall fan pressure ratio, selecting a second operating power level that is lower than the first operating power level and reducing the flow in the aft fan rotor and pressurizing to a second tip pressure ratio to generate a second overall pressure ratio that is substantially lower than the first overall fan pressure ratio while the flow rate in the front fan stage is held substantially constant.
摘要:
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.