Patent Description:
Gas turbine engines are known to power aircraft. In a gas turbine engine, a fan delivers air into a bypass duct as propulsion air, and also into a compressor. The compressor compresses the air and delivers it into a combustor and is mixed with fuel and ignited. Products of the combustion pass downstream over turbine rotors, driving them to rotate. The turbine rotors in turn drive the fan and compressor rotors.

A core housing surrounds the compressor, combustor and turbine sections. A nacelle is spaced radially outwardly of the core housing and the fan to define the bypass duct.

Historically gas turbine engines have been mounted to the underside of the wings, or to the fuselage of the aircraft. It has also been proposed to mount gas turbine engines above the wing of an aircraft.

<CIT> discloses a gas turbine engine with an ejector and <CIT> discloses a noise-shielding wing configuration.

The present invention provides a gas turbine engine and engine mount structure as set forth in claim <NUM>.

In another embodiment, the nacelle includes D-doors which can be pivoted outwardly away from the core housing to provide access to inside the engine.

In another embodiment, at least one of the D-doors has an attachment that provides a support for maintenance workers when the D-doors are in an open position.

In another embodiment, a second plane is defined perpendicular to the first plane and also extends through the axis of rotation, and the engine mount structure is on one side of the second plane and an auxiliary gearbox driven by the turbine section is positioned on a second side of the second plane.

In another embodiment, an oil tank is also mounted in the opposed side.

In another embodiment, a pre-cooler is provided in a side of the second plane from which engine mount structure extends.

In another embodiment, wherein the nacelle is formed to be non-perpendicular to the axis of rotation at a trailing edge of the nacelle.

In another embodiment, the nacelle is formed to be perpendicular to the axis of rotation at a trailing edge of the nacelle.

An aircraft includes a fuselage and a pair of wings extending laterally outwardly of the fuselage. The wings include a relatively straight portion between the fuselage and a gas turbine engine, and a swept portion laterally outwardly of the gas turbine engine relative to the fuselage. An engine mount structure attaches the gas turbine engine to the relatively straight portion, and vertically above the wings. The gas turbine engine has a core engine including a compressor section, a combustor section and a turbine section mounted within a core engine housing. The fan, the compressor section and the turbine section rotate about an axis of rotation. An outer nacelle surrounds the fan, and is spaced from the core engine housing to define a bypass duct. The fan delivers air into the bypass duct and into the core housing. The nacelle is formed with camber so as to be curved in a first plane defined parallel to the horizontal and away from the axis of rotation in a first lateral direction. The engine mount structure extends from the nacelle at an angle that is non-parallel and non-perpendicular to the first plane, and has a component in a lateral direction that is opposed to the first lateral direction.

In an embodiment, a first distance is defined by a first chord of the swept portion of the wings immediately laterally outwardly of the nacelle on each the gas turbine engine. A first distance is defined between a leading edge of the swept portion of the wing and a trailing edge of the nacelle. A ratio of the first distance to the first chord is greater than or equal to <NUM>% and less than or equal to <NUM>%.

In another embodiment, a second chord is defined between a leading edge of the straight portion of the wings and a trailing edge of the straight portion of the wings. A second distance is defined between the leading edge of the straight portion of the wings and the trailing edge of the nacelle, and a ratio of the second distance and the second chord is greater than or equal to <NUM>% and less than or equal to <NUM>%.

In another embodiment, a second plane is defined perpendicular to the first plane and also extending through the axis of rotation. The engine mount structure is on one side of the second plane and an auxiliary gearbox driven by the turbine section is positioned on a second side of the second plane.

In another embodiment, at least one component associated with each the gas turbine engine are mounted within the straight portion of the wings.

In another embodiment, a drive shaft is driven by the turbine section of the gas turbine engine and drives at least one the component.

In another embodiment, at least one component includes at least one of an oil tank and batteries or controllers.

In another embodiment, the engine mount structure extends along an angle away from the axis of rotation defined away from the first plane, and the angle is between <NUM> and <NUM> degrees.

These and other features can be best understood from the following specification and drawings, the following which is a brief description.

In a further example, the engine <NUM> bypass ratio is greater than about six (<NUM>:<NUM>), with an example embodiment being greater than about ten (<NUM>:<NUM>), the geared architecture <NUM> is an epicyclic gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about <NUM> and the low pressure turbine <NUM> has a pressure ratio that is greater than about five. In one disclosed embodiment, the engine <NUM> bypass ratio is greater than about ten (<NUM>:<NUM>), the fan diameter is significantly larger than that of the low pressure compressor <NUM>, and the low pressure turbine <NUM> has a pressure ratio that is greater than about five (<NUM>:<NUM>).

<FIG> shows an aircraft <NUM> having a fuselage <NUM> and wings <NUM>. Engines <NUM> are mounted above the wings <NUM>. A nacelle <NUM> provides the outer surface of the engines <NUM>, as known. The engines <NUM> may be similar to the engine shown in <FIG>, or could be direct drive engines.

The wings <NUM> include a relatively straight section <NUM> extending between the fuselage <NUM> and the nacelle <NUM> and a swept wing portion <NUM> which is laterally outward of the engine <NUM>.

<FIG> shows the wings <NUM>, engine <NUM> and fuselage <NUM> from the side.

The prior art engines mounted underneath the wing are constrained by ground clearance. Recently gas turbine engines are being provided with higher bypass ratios. However, this typically requires a larger nacelle such that the bypass duct can be larger. The ground clearance constraint limits the amount of increase of the bypass ratio. An over wing mount provides relief from this constraint, and also provides potential fuel burn and noise benefits. Further, there is less drag than an under wing installation.

<FIG> shows details of the engine <NUM>. The swept wing portion <NUM> has a chord distance defined parallel to an axis of rotation X of the engine <NUM> between a leading edge <NUM> and a trailing edge <NUM> of the swept wing portion <NUM>. This chord is labeled d<NUM> as is measured at a location where the swept wing portion begins, immediately outward of nacelle <NUM>. A second length d<NUM> is defined between the leading edge <NUM> and a trailing edge <NUM> of nacelle <NUM>.

A chord length d<NUM> is defined between a leading edge <NUM> and a trailing edge <NUM> of the straight section <NUM> of the wing <NUM>. A fourth distance d<NUM> is defined between the leading edge <NUM> of the straight section <NUM> of the wing and the trailing edge <NUM> of the nacelle. All of these distances are measured parallel to the axis of rotation of the engine <NUM>.

In an embodiment, a ratio of d<NUM> to d<NUM> is greater than or equal to <NUM>% and less than or equal to <NUM>%, and in embodiments greater than or equal to <NUM>% and less than or equal to <NUM>% and in one embodiment <NUM>%.

A ratio of d<NUM> to d<NUM> is less than or equal to <NUM>% and greater than or equal to <NUM>%, and in embodiments less than or equal to <NUM>% and greater than or equal to <NUM>%, and in other embodiments less than or equal to <NUM>% and greater than or equal to <NUM>%, and in one embodiment <NUM>%.

<FIG> shows an engine <NUM> having the nacelle 106a. The trailing edge <NUM> has "scarf" or is at a non-perpendicular angle relative to an axis of rotation X of the engine <NUM> within the nacelle 106a. The scarf may be found in a view looking downwardly of a nacelle, and from the side. It is essentially a degree of freedom that allows fine tuning of a wing nacelle exhaust interaction. Essentially, it allows fine tuning of the inboard nacelle wall linked to interact with the inboard part of the wing independently of the outboard nacelle wall interaction with the outboard wing. It also provides control of an exhaust plume with regard to both inboard and outboard wing flow fields. The nacelle 106a is provided with camber <NUM>. Essentially camber means that a center point of the nacelle 106a is not formed on a straight line parallel relative to the axis of rotation X of the gas turbine engine <NUM>, in a plane which is parallel to the horizontal, and extending through the axis of rotation X. As can be appreciated, the line of camber <NUM> extends away from the fuselage <NUM>. While the line of camber <NUM> is shown as a simple curve in this Figure and in practice it may be much more complex. In one example the line of camber may be similar to those of super critical airfoils.

<FIG> shows a nacelle 106b also having camber <NUM>. Nacelle 106b does not have scarf, or zero scarf, but rather has its trailing edge <NUM> being perpendicular to the axis of rotation X.

The camber shape improves wing leading edge suction through the rapid acceleration of the airflow, terminating in a shock wave in the forward portion of the wing. A symmetric nacelle would create a shock system that reduces lift and drag benefits of leading edge suction on both the straight section <NUM> and swept section <NUM>. Cambering the nacelle <NUM> tailors the shock structure on the wing, making the net effect beneficial.

Nacelle camber enables a beneficial drag reduction in a transonic speed regime. This provides benefits to an over wing mount of an engine.

<FIG> shows an engine <NUM> having an engine mount structure <NUM> for mounting to the straight wing portion <NUM>. A core engine <NUM> is shown within the nacelle <NUM>. The nacelle <NUM> is shown to have a separation line <NUM> and pivot axes <NUM>. It should be understood that the forward most portion of the nacelle <NUM> would not necessarily have the separation line <NUM>, and one might not be able to see the pivot axes <NUM>. However, the view of <FIG> is shown to illustrate D-doors <NUM> and <NUM>. The pivot axes <NUM> are associated with engine mount structure <NUM>.

As shown in <FIG>, since the engine mount structure <NUM> is at an angle which is non-vertical, so that when the D-doors <NUM> and <NUM> are open there will be easier access to the interior of the engine, than if the engine mount structure extended vertically.

This is illustrated in <FIG> where maintenance work is occurring to the engine <NUM>. Notably, a maintenance support attachment <NUM> is provided that may function as a step or seat for a maintenance worker.

In an engine mounted beneath the wing, the engine mount structure would typically extend vertically to connect the engine to the wing. The D-doors can pivot to open upwardly, allowing maintenance access from underneath the wing. However, applicant has recognized an engine mounted through a vertically extending engine mount structure above the wing would have the D-doors open in a way where one could not gain access to the engine.

In addition, the angled engine mount structure reduces engine mount structure weight, and reduces the structure required to connect the engine to the wing.

<FIG> schematically shows a feature of the engine mount structure <NUM> relative to the axis of rotation X of the core engine <NUM>. A first plane P could be defined which extends through the axis of rotation X. This plane P would be parallel to the horizontal when the engine is mounted on an aircraft.

The engine mount structure <NUM> extends vertically downwardly from the plane P and laterally outwardly of the axis of rotation X, and defines an angle A relative to the first plane P. Angle A may be in a range of <NUM> to <NUM> degrees. That is, the angle A could be said to be non-parallel and non-perpendicular to the plane P.

<FIG> shows that relative to the axis of rotation X, the line of camber <NUM> is curved laterally away in an opposed direction to the lateral extension direction of the engine mount structure <NUM>.

<FIG> shows repositioning modifications because of the angled mount of the engine mount structure <NUM>. An auxiliary gearbox <NUM> is shown on an opposed side of a second plane Z from engine mount structure <NUM>. The plane Z is perpendicular to the first plane P. Historically, the auxiliary gear box would be mounted at bottom dead center, or bisected by plane Z. However, the engine mount structure <NUM> might interfere with this location. As such, as shown, the location of the auxiliary gearbox <NUM> is rotated to be in an opposed side of the plane Z from the location of the engine mount structure <NUM>. Similarly, the oil tank <NUM> may also be relocated to that side. A precooler <NUM> may be positioned on the same side of the plane Z as the engine mount structure <NUM>. The oil tank <NUM> and gearbox <NUM> often require maintenance, and thus would not be in the position of the precooler <NUM>. In the illustrated position, the oil tank <NUM> and gearbox <NUM> would be accessible. However, precooler <NUM> typically sees less maintenance, and thus can be in this position.

<FIG> shows yet another feature of an over wing mount, and includes utilizing the straight wing section <NUM> for positioning engine components. A power take-off <NUM> extends from the core engine <NUM> of the engine <NUM>. Shaft may drive a component <NUM> within the forward space of the straight wing portion <NUM>. Component <NUM> may include larger generators and motors mounted here to use the extra space. Further, fluid lines <NUM> are shown schematically, and may communicate back to the engine <NUM>. Further, this space can be utilized for an oil tank, hybrid electric batteries and/or controllers.

The angled engine mount structure further facilitates the placement of these components in the straight wing portion <NUM>. This is true because oil and electric lines must be routed from the core of the engine to the motors and/or tanks, and this would typically be done by routing the lines through a nacelle bifurcation. With a vertical engine mount structure this would require them to be routed down and then over, resulting in longer and more complex connection than with the angled engine mount structure.

A gas turbine engine and engine mount structure could be said to include a core engine housing including a compressor section, a combustor section and a turbine section, a fan. The fan, the compressor section and the turbine section rotate about an axis of rotation. An outer nacelle surrounds the fan, and is spaced from the core engine housing to define a bypass duct. The fan delivers air into the bypass duct and into the core engine housing. The nacelle is formed with camber so as to be curved in a first plane away from the axis of rotation in a first lateral direction, and an engine mount structure extending from the nacelle at an angle that is non-parallel and non-perpendicular to the first plane, and having a component in a lateral direction that is opposed to the first lateral direction.

An aircraft could be said to include a fuselage and a pair of wings extending laterally outwardly of the fuselage. The wings include a relatively straight portion between the fuselage and a gas turbine engine, and a swept portion laterally outwardly of said gas turbine engine relative to said fuselage. An engine mount structure attaches the gas turbine engine to the straight portion, and vertically above the wings. The gas turbine has a core engine housing including a compressor section, a combustor section and a turbine section, a fan. The fan, the compressor section and the turbine section rotate about an axis of rotation. An outer nacelle surrounds the fan, and is spaced from the core engine housing to define a bypass duct. The fan delivers air into the bypass duct and into the core housing. The nacelle is formed with camber so as to be curved in a first plane defined parallel to the horizontal and extending through the axis of rotation away from the axis of rotation in a first lateral direction. The engine mount structure extends from the nacelle at an angle that is non-parallel and non-perpendicular to the first plane, and having a component in a lateral direction that is opposed to the first lateral direction.

Claim 1:
A gas turbine engine (<NUM>, <NUM>) and engine mount structure (<NUM>) comprising:
a core engine including a compressor section (<NUM>), a combustor section (<NUM>) and a turbine section (<NUM>) mounted within a core engine housing;
a fan (<NUM>), said fan (<NUM>), said compressor section (<NUM>) and said turbine section (<NUM>) rotating about an axis of rotation (X); and
an outer nacelle (<NUM>; 106a; 106b) surrounding said fan (<NUM>), and being spaced from said core engine housing to define a bypass duct, said fan (<NUM>) delivering air into said bypass duct and into said core engine housing, said nacelle (<NUM>; 106a; 106b) being formed with camber (<NUM>) such that a center point of the nacelle (<NUM>; 106a; 106b) extends along a curve in a first plane (P) away from said axis of rotation (X) in a first lateral direction, such that the line of camber (<NUM>) is configured to extend away from a fuselage (<NUM>) of an aircraft,
the first plane (P) being parallel to the horizontal and extending through the axis of rotation (X), the engine mount structure (<NUM>) extending from said nacelle (<NUM>; 106a; 106b) at an angle (A) that is non-parallel and non-perpendicular to said first plane (P), and the engine mount structure (<NUM>) extending in a direction, the direction having a component in a lateral direction that is opposed to said first lateral direction.