Patent Application
20170009704
A typical cascade-style, translating sleeve thrust reverser for a turbofan propulsion system includes a circumferential array of cascades. Cascades are frequently grill- or grate-like structures through which the majority of the fan bypass air from the propulsion system passes through during reverse thrust operation. The cascades shapes the efflux of air in predetermined directions to produce reverse thrust whilst at the same time ensuring acceptable engine re-ingestion and aircraft stability and control is maintained during reverse operation. Often, a cascade array will contain low forward-turning vanes in a lower, inboard quadrant of the thrust reverser, and high forward-turning vanes in other quadrants (of course, other variations may be possible to suit the particular needs of a given aircraft). The low forward-turning vane cascades direct air outward from the thrust reverser, but only slightly forward, to avoid engine re-ingestion and fuselage-mounted instrumentation efflux impingement from occurring. High forward-turning vane cascades direct air outward and in a more forward direction to generate reverse thrust more efficiently than the low forward-turning vane cascades.
This disclosure proposes an improved packaging solution for a thrust reverser with both low forwarding-turning vane cascades and high forward-turning vane cascades.
The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosure. The summary is not an extensive overview of the disclosure. It is neither intended to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure. The following summary merely presents some concepts of the disclosure in a simplified form as a prelude to the description below.
Aspects of the disclosure are directed to a system configured for use in connection with a thrust reverser of an aircraft, comprising a first array of cascades, a second array of cascades, a sleeve configured to selectively block or unblock the first and second arrays of cascades, where the sleeve is configured such that when the thrust reverser is stowed a first portion of an interface associated with the sleeve is at a first axial location and a second portion of the interface is at a second axial location that is different from the first axial location, where the first axial location substantially coincides with a first circumferential positioning of the first array of cascades and the second axial location substantially coincides with a second circumferential positioning of the second array of cascades. In some embodiments, the first axial location is further aft than the second axial location. In some embodiments, the first array of cascades are configured to project a first efflux plume in generating reverse thrust, and the second array of cascades are configured to project a second efflux plume in generating reverse thrust. In some embodiments, the first array of cascades are configured to project the first efflux plume in a forward direction in a first amount, and the second array of cascades are configured to project the second efflux plume in the forward direction in a second amount. In some embodiments, the second amount is greater than the first amount. In some embodiments, a third portion of the interface couples the first portion of the interface and the second portion of the interface. In some embodiments, the third portion of the interface is substantially perpendicular to the first portion of the interface. In some embodiments, the third portion of the interface is substantially perpendicular to the second portion of the interface. In some embodiments, the second portion of the interface corresponds to a split line between the sleeve and a cowl of a fan case. In some embodiments, the system further comprises a structural member located towards an aft end of the cowl. In some embodiments, the structural member is positioned at substantially the first circumferential positioning of the first array of cascades. In some embodiments, the structural member is configured as a stationary panel that is separate from the cowl. In some embodiments, the structural member is configured as an extension of the cowl. In some embodiments, the first cascades are configured to project an efflux plume in generating reverse thrust, and when the thrust reverser is fully deployed the sleeve is clear of the efflux plume.
Aspects of the disclosure are directed to a system configured for use in connection with a thrust reverser of an aircraft, comprising a first array of cascades, a second array of cascades, a translating sleeve configured to selectively block or unblock the first and second arrays of cascades, where when the thrust reverser is stowed a forward edge of the sleeve is staggered so as to be positioned at a first axial location and a second axial location, where the first axial location substantially coincides with a first circumferential positioning of the first array of cascades and the second axial location substantially coincides with a second circumferential positioning of the second array of cascades. In some embodiments, the first axial location is further aft than the second axial location. In some embodiments, the first array of cascades are configured to project a first efflux plume in a forward direction in a first amount in generating reverse thrust, and the second array of cascades are configured to project a second efflux plume in the forward direction in a second amount in generating reverse thrust, and the second amount is greater than the first amount. In some embodiments, the sleeve is configured to translate in a forward direction to block the first and second arrays of cascades, and the sleeve is configured to translate in an aft direction to unblock the first and second arrays of cascades. In some embodiments, the system further comprises a blocker door configured to redirect at least a first portion of a bypass flow through the first cascades and a second portion of the bypass flow through the second cascades when the thrust reverser is deployed.
The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements.
It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities.
In
Referring now to
The nacelle 200 may include one or more of a fan cowl 201 a thrust reverser, an exhaust nozzle 214 and a centerbody 216. The fan cowl 201 generally overlaps a fan case 202 which helps define a radially exterior surface of the fan duct. The thrust reverser is aft of the fan case 202 and defines the remainder of the fan duct until the fan bypass air exits the propulsion system through a bypass air nozzle. The thrust reverser includes a translating sleeve 204.
The sleeve 204 may be configured to translate in the forward or aft direction.
The cascades 254a and 254b may be representative of one or more arrays of cascades. In embodiments where the nacelle 200 is coupled to the wing of an aircraft, the cascades 254b may be positioned closer to the wing than the cascades 254a.
The cascades 254a may be low forward-turning vane cascades and the cascades 254b may be high forward-turning vane cascades.
In accordance with many conventional nacelle designs, an interface/split line between the trailing edge of the fan cowl 201 and the leading edge of the outer panel of the sleeve 204 when the thrust reverser is stowed may generally be located at a single axial location over the circumference of the nacelle.
In comparison, in
The portion 223b of the split line 223 may be associated/coincide with the interface between the fan cowl 201 and the sleeve 204, radially outward from the cascades 254b. The portion 223a of the split line 223 may be associated with (or coincident with) the cascades 254a. The portion 223a may be at a different axial position relative to the portion 223h; for example, the portion 223a may be located further aft than the portion 223b. The portion 223c-1 may join the portions 223a and 223b. In
In view of the shape/profile of the split line 223 of
Referring now to
In general, with high and low forward-turning vane arrays of the same axial length, the staggering and aft transposition of the translating sleeve outer panel leading edge over the low forward-turning vane array eliminates the need to block some of the aft most cascade baskets. Because the air flow is increased compared to a cascade array design where some of the baskets must be blocked, the overall dimension of the array may be reduced, and the overall size and weight of the thrust reverser will be correspondingly minimized.
Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications, and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure.
