A gas turbine engine component has a component body configured to be positioned within a flow path of a gas turbine engine having an external pressure, and wherein the component body includes at least one internal cavity having an internal pressure. At least one inlet opening is formed in an outer surface of the component body to direct hot exhaust gas flow into the at least one internal cavity, and there is at least one outlet from the internal cavity. The internal pressure is less than an inlet external pressure at the inlet opening and the internal pressure is greater than an outlet external pressure at the outlet opening to controllably ingest hot exhaust gas via the inlet opening and expel the hot exhaust gas via the outlet opening to maintain a laminar boundary layer along the outer surface of the component body.

A gas turbine engine comprises a housing having an inlet leading to a fan rotor. A bypass door is mounted upstream of the inlet to the fan rotor, and is moveable away from a non-bypass position to a bypass position to selectively bypass boundary layer air vertically beneath the engine. An aircraft is also disclosed.

Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle (501) defining a duct, and a fan located therewithin. The fan comprises a hub arranged to rotate around a rotational axis (A-A) and a plurality of blades attached thereto. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r [0, 1]), and leading and trailing edges defining, for each span position, a chord therebetween to having a chord length (c). For each of said plurality of blades, the ratio of chord length at the 0 percent span position (c.sub.hub) to chord length at the 100 percent span position (c.sub.tip) is 1 or greater.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft includes a nacelle (501) defining a duct (502), and a fan (503) located therewithin. The fan comprises a hub which rotates around a rotational axis (A-A) and a plurality of blades attached thereto. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r [0, 1]), a leading edge and a trailing edge defining, for each span position, a chord therebetween having a chord length (c), and a blade thickness (t) defined for each span position thereof. For each blade, a ratio of thickness at the 0 percent span position (t.sub.hub) to chord length is 0.1 or greater.

Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

An active laminar flow control arrangement may comprise a variable speed constant frequency (VSCF) converter comprising a housing, a compressor, an electric motor operably coupled to the compressor, and a laminar flow control duct. An airflow is received by the housing from the laminar flow control duct in response to the electric motor driving the compressor for cooling the VSCF converter.

To provide a blade of a fan or compressor that is reduced in loss by enlarging a laminar flow region over a blade surface. A blade according to the present disclosure is divided into a subsonic region where the relative Mach number of the inlet air flow during rated operation of a turbofan engine is lower than 0.8 and a transonic region where the relative Mach number is equal to or higher than 0.8. Provided that a parameter () defined according to =(in)/(inex) is referred to as a blade surface angle change rate where denotes an angle formed by a tangent to the blade surface and the axial direction of the turbofan engine, in denotes the blade surface angle at the leading edge of the blade, and the ex denotes the blade surface angle at the trailing edge, in each of the subsonic region and the transonic region, the minimum value of the blade surface angle change rate on the pressure surface, an upper limit value of the blade surface angle change rate at a predetermined axial location along the chord on the pressure surface, and an upper limit value and a lower limit value of the blade surface angle change rate at a predetermined axial location along the chord on the suction surface are defined.

A steam turbine having an inflow ring channel which is connected to an inflow connecting piece in terms of flow technology. The inflow connecting piece is designed in such a way that an incoming flow is first slowed down, subsequently accelerated and simultaneously deflected.

The invention concerns an air inlet in a surface. The air inlet includes an opening in the surface having a longitudinal axis, wherein a fluid is intended to flow over the air inlet in the direction of the longitudinal axis, and wherein the opening has an upstream edge and a downstream edge. The air inlet furthermore comprises an outflow channel which adjoins the opening and extends at an angle to the surface, wherein the outflow channel has an inner wall with an upstream casing surface and a downstream casing surface. It is provided that the opening adjoining the upstream edge is partly or completely covered by a lattice and that the outflow channel has a bulge which protrudes into the outflow channel in the region of its upstream casing surface, constantly increases in thickness in the longitudinal direction of the outflow channel adjoining the upstream edge, forms a thickness maximum (d.sub.max) and after the thickness maximum (d.sub.max), constantly decreases in its thickness.