Partial cascade thrust reverser
View Patent ↗A thrust reverser for a jet engine comprises a translating wall section moveable between a stowed position and a deployed position. The translating wall section is adjacent an annular fan duct wall or other fixed portion of the jet engine when in the stowed position and is separated from the annular fan duct wall when in the deployed position, thereby creating an aperture through which a fluid stream passes. A fluid flow reverser element directs the fluid stream in a direction generally forward relative to the jet engine when the translating wall section is in the deployed position. The fluid flow reverser element extends only partially into the fluid stream such that only a first portion of fluid of the fluid stream engages the fluid flow reverser element. A second portion of the fluid stream is entrained in the first portion and is thereby directed forward relative to the jet engine.
1. A thrust reverser for a jet engine, said thrust reverser comprising:
a translating wall section moveable between a first position and a second position, said translating wall section being adjacent a fixed portion of said jet engine when in said first position, at least a portion of said translating wall section being separated from said fixed portion of said jet engine by a space when said translating wall section is in said second position thereby creating an aperture between said fixed portion of said jet engine and said translating wall section, wherein the aperture is bounded by a forward edge defined by said fixed portion and an aft edge defined by said translating wall section; and
a fluid flow reverser element having a forward edge and an aft edge fixed relative to the translating wall section and configured for directing a fluid flow in a direction generally forward relative to said jet engine when said translating wall section is in said second position, said fluid flow reverser element extending only partially into a fluid stream passing through said aperture such that a first portion of fluid of said fluid stream engages said fluid flow reverser element and a second portion of fluid of said fluid stream does not engage the fluid flow reverser element and is entrained within the first portion of the fluid stream,
wherein a first distance between said forward edge and said aft edge of said fluid flow reverser element is less than a second distance between said forward edge and said aft edge of said aperture.
2. The thrust reverser as set forth in claim 1 , further comprising a support element securing a first end of said fluid flow reverser element, said fluid flow reverser element being supported on said jet engine solely by said support element when said translating wall section is in said second position.
3. The thrust reverser as set forth in claim 2 , further comprising an actuator for driving said support element to move said translating wall section from said first position to said second position.
4. The thrust reverser as set forth in claim 1 , wherein said first portion of fluid of said fluid stream engaging said fluid flow reverser element is within the range of from ⅛ to ⅞.
5. The thrust reverser as set forth in claim 1 , wherein said first portion of fluid of said fluid stream engaging said fluid flow reverser element is within the range of from ⅜ to ⅝.
6. The thrust reverser as set forth in claim 1 , wherein said fluid flow reverser element extends into an aft portion of said fluid stream.
7. The thrust reverser as set forth in claim 1 , said fluid flow reverser element comprising an array of arcuate vanes.
8. The thrust reverser as set forth in claim 1 , the aperture and the fluid flow reverser element each substantially circumscribing the jet engine.
9. The thrust reverser as set forth in claim 1 , wherein a ratio of said first distance between said forward edge and said aft edge of said fluid flow reverser element to said second distance between said forward edge and said aft edge of said aperture is within the range of from ⅛ to ⅞.
10. The thrust reverser as set forth in claim 9 , wherein a ratio of said first distance between said forward edge and said aft edge of said fluid flow reverser element to said second distance between said forward edge and said aft edge of said aperture is within the range of from ⅜ to ⅝.
11. A thrust reverser for a jet engine, said jet engine including an annular casing circumscribing a fluid flow duct, said thrust reverser comprising:
a translating wall section moveable between a first wall position and a second wall position, said translating wall section being adjacent said annular casing when in said first wall position, at least a portion of said translating wall section being separated from said annular casing by a space when said wall section is in said second wall position thereby creating an aperture between said annular casing and said translating wall section, said aperture bounded by a forward aperture edge defined by said annular casing and an aft aperture edge defined by said translating wall section;
a cascading flow reverser supported by said translating wall section for directing a fluid flow in a direction generally forward relative to said jet engine when in said second wall position, said reverser extending only partially into a path of a fluid flowing through said aperture such that a first portion of said fluid flowing through said aperture engages said reverser and a second portion of said fluid flowing through said aperture does not engage the reverser and is entrained within the first portion of the fluid flowing through said aperture, said cascading flow reverser including a forward reverser edge and an aft reverser edge, wherein a first distance between said forward reverser edge and said aft reverser edge is less than a second distance between said forward aperture edge and said aft aperture edge, wherein when the translating wall section is in the second wall position, the portion of the aperture between the annular casing and the forward edge of the cascading flow reverser does not have any other structural components impeding the fluid stream; and
a blocker door operably connected to said translating wall section such that when said translating wall section moves from said first wall position to said second wall position, said blocker door moves from a first door position to a second door position, said second door position being interposed in said fluid flow duct.
12. The thrust reverser as set forth in claim 11 , further comprising a support element securing a first end of said cascading flow reverser, said cascading flow reverser being supported on said jet engine solely by said support element when said translating wall section is in said second wall position.
13. The thrust reverser as set forth in claim 12 , further comprising an actuator for driving said support element to move said translating wall section from said first wall position to said second wall position.
14. The thrust reverser as set forth in claim 11 , wherein a ratio of said first distance between said forward reverser edge and said aft reverser edge of said cascading flow reverser to said second distance between said forward aperture edge and said aft aperture edge of said aperture is within the range of from ⅛ to ⅞.
15. The thrust reverser as set forth in claim 11 , wherein a ratio of said first distance between said forward reverser edge and said aft reverser edge of said cascading flow reverser to said second distance between said forward aperture edge and said aft aperture edge of said aperture is within the range of from ⅜ to ⅝.
16. A thrust reverser for a jet engine, said jet engine including an annular fan casing circumscribing a fluid flow duct, said thrust reverser comprising:
a sleeve including—
a translating wall section, and
a translating cowling,
said sleeve moveable between a first sleeve position and a second sleeve position, said sleeve being adjacent said annular fan casing when in said first sleeve position, at least a portion of said sleeve being separated from said annular fan casing by a space when said sleeve is in said second sleeve position thereby creating an aperture between said annular fan casing and said translating sleeve, said aperture providing a fluid flow path from said fluid flow duct to an outside of said jet engine, said aperture bounded by a forward aperture edge defined by said annular fan casing and an aft aperture edge defined by said sleeve;
a cascading fluid flow reverser supported by said sleeve for directing a fluid flow in a direction generally forward relative to said jet engine when in said second sleeve position, said reverser extending only partially into said fluid flow path such that a first portion of a fluid flowing through said aperture engages said reverser and a second portion of said fluid flowing through said aperture does not engage the reverser and is entrained within the first portion of the fluid flowing through said aperture, and said reverser including a forward reverser edge and an aft reverser edge, wherein a first distance between said forward reverser edge and said aft reverser edge is less than a second distance between said forward aperture edge and said aft aperture edge wherein when the sleeve is in the second sleeve position, the portion of the aperture between the annular fan casing and the forward edge of the cascading fluid flow reverser does not have any other structural components impeding the fluid stream; and
a blocker door operably connected to the sleeve such that when said sleeve moves from said first sleeve position to said second sleeve position, said blocker door moves from a first door position to a second door position, said second door position being interposed in said fluid flow duct.
17. The thrust reverser as set forth in claim 16 , wherein said cascading fluid flow reverser is supported by said sleeve at a forward end of the translating wall section.
18. The thrust reverser as set forth in claim 16 , wherein a ratio of said first distance between said forward reverser edge and said aft reverser edge to said second distance between said forward aperture edge and said aft aperture edge is within the range of from ⅛ to ⅞.
19. The thrust reverser as set forth in claim 16 , wherein a ratio of said first distance between said forward reverser edge and said aft reverser edge to said second distance between said forward aperture edge and said aft aperture edge is within the range of from ⅜ to ⅝.
20. A method of reversing the thrust of a jet engine, the method comprising:
moving a translating wall section from a first wall position adjacent a fixed portion of said jet engine to a second wall position separated from said fixed portion by a space thereby creating an aperture between said translating wall section and said fixed portion;
moving a blocker door from a first door position to a second door position, wherein said blocker door impedes an internal fluid stream through said jet engine when in said second door position thereby directing said fluid stream through said aperture; and
placing a fluid flow reverser element such that said fluid flow reverser element engages a first portion of fluid of said fluid stream and directs said first portion of fluid in a direction generally forward relative to said jet engine and such that a second portion of fluid of said fluid stream does not engage the fluid flow reverser element and is entrained within the first portion of the fluid stream.