A forced induction device (100) includes: a rotor (1) which includes a turbine side shaft portion (11), a compressor side shaft portion (12), and a connection shaft portion (13) connecting these to each other; a turbine side bearing (5) which supports the turbine side shaft portion (11); and a compressor side bearing (6) which supports the compressor side shaft portion (12). A rigidity of the connection shaft portion (13) is lower than that of the turbine side shaft portion (11) and the compressor side shaft portion (12) so that a node in a mode shape at each critical speed involving with an operating rotational speed region of the rotor (1) is located between the turbine side bearing (5) and the compressor side bearing (6).

A forced induction device (100) includes: a rotor (1) which includes a turbine side shaft portion (11), a compressor side shaft portion (12), and a connection shaft portion (13) connecting these to each other; a turbine side bearing (5) which supports the turbine side shaft portion (11); and a compressor side bearing (6) which supports the compressor side shaft portion (12). A rigidity of the connection shaft portion (13) is lower than that of the turbine side shaft portion (11) and the compressor side shaft portion (12) so that a node in a mode shape at each critical speed involving with an operating rotational speed region of the rotor (1) is located between the turbine side bearing (5) and the compressor side bearing (6).

A gear reduction reduces a speed of a fan rotor relative to a speed of a fan drive turbine. A fan case surrounds the fan rotor. A core engine has a compressor section and includes a low pressure compressor. The fan rotor delivers air into a bypass duct defined between the fan case and the core engine. A rigid connection between the fan case and the core engine includes a plurality of aft connecting members rigidly connected to the fan case, and to the core engine. A plurality of fan exit guide vanes are rigidly connected to the fan case, with the fan exit guide vanes including structural fan exit guide vanes which are rigidly connected to the core engine, and non-structural fan exit guide vanes, and the non-structural fan exit guide vanes being provided with an acoustic feature to reduce noise.

A centrifugal compressor of an aircraft engine includes an impeller and a shroud extending circumferentially around the impeller. A bellmouth disposed upstream of the impeller extends circumferentially and includes: a conduit section extending from a first end to an upstream-most location of the bellmouth, the first end of the conduit section secured to the shroud, and a peripheral section extending from the upstream-most location to a second end located radially outwardly of the first end, the peripheral section located radially outwardly of the conduit section and axially overlapping the conduit section. A stiffening member is located on the peripheral section of the bellmouth proximate the second end. The stiffening member extends circumferentially and provides the bellmouth with a dynamic vibration mode outside a range of dynamic vibration modes of the aircraft engine during operation.

A centrifugal compressor of an aircraft engine includes an impeller and a shroud extending circumferentially around the impeller. A bellmouth disposed upstream of the impeller extends circumferentially and includes: a conduit section extending from a first end to an upstream-most location of the bellmouth, the first end of the conduit section secured to the shroud, and a peripheral section extending from the upstream-most location to a second end located radially outwardly of the first end, the peripheral section located radially outwardly of the conduit section and axially overlapping the conduit section. A stiffening member is located on the peripheral section of the bellmouth proximate the second end. The stiffening member extends circumferentially and provides the bellmouth with a dynamic vibration mode outside a range of dynamic vibration modes of the aircraft engine during operation.

An energy dissipating damper includes a first end portion configured to be coupled to a first structure, a second end portion, opposite the first end portion, configured to contact a second structure, and a body portion extending from the first end portion to the second end portion. The body portion includes a plurality leaves. The plurality of leaves may be fixed together at the first end portion and may be separable from each other at the second end portion. In response to the energy dissipating damper being in a loaded state, the plurality of leaves may be in direct contact with each at the second end portion. The energy dissipating damper may further include a contact element coupled to the second end portion, and the contact element may comprise an abradable material.

[Object] To observe the sign or occurrence of an unstable operation of a turbo-machine. [Solving Means] An observation apparatus 1 includes: a detection unit 10 including one or two or more sensors 11, 12 that are disposed in a turbo-machine 2, are highly time responsive, and observe unsteady fluctuations of the turbo-machine 2; a computation unit 20 that output signals from the one or two or more sensors 11, 12 every moment, stores time series data for a predetermined period, and calculates in real time a parameter for detecting an unstable operation of the turbo-machine; and a determination unit 30 that compares the parameter for detecting the unstable operation with a predetermined threshold and outputs in real time a determination result of a sign or occurrence of the unstable operation.

A fan assembly includes a fan duct, an inlet fan, an outlet guide vane assembly, and a control system. The inlet fan includes fan blades adapted to rotate about a central axis to force fan exit air toward an aft end of the fan duct. The outlet guide vane assembly is located in the fan duct downstream of the inlet fan and is configured to adjust a direction of the fan exit air. The outlet guide vane assembly includes a plurality of guide vanes that extend radially relative to the central axis and are configured to rotate to a first vane-pitch angle. The control system is configured to rotate the guide vanes redirect the fan exit air, vary a pressure downstream of the fan inlet, minimize intake flow distortion experienced by the inlet fan, reduce inlet fan vibratory response and/or improve fan operability margins.

A fan assembly includes a fan duct, an inlet fan, and an outlet guide vane assembly. The inlet fan includes blades adapted to force fan exit air toward an aft end of the fan duct. The outlet guide vane assembly is located in the fan duct downstream of the inlet fan and is configured to adjust a direction of the fan exit air received from the blades. The outlet guide vane assembly includes a first plurality of vanes configured to rotate to redirect the fan exit air in a first direction, and a second plurality of vanes located downstream of the first plurality of vanes. The second plurality of vanes are configured to rotate to redirect the fan exit air flowing in the first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the first vanes.

Methods, apparatus, systems and articles of manufacture are disclosed. An inner shroud damper for a gas turbine engine includes: at least one carrier including a joint to couple to an inner shroud, the at least one carrier having a first side and a second side, and at least one mass damper coupled to the at least one carrier.