Outflow valve for an aircraft
The invention relates to a valve for controlling a fluid flow from a first environment to a second environment, having a frame for disposing a separating element in the region of an opening, said element separating the first environment from the second environment, and a first flap and a second flap for controlling the fluid flow through the opening between the first environment and the second environment, the flaps being movable in the frame. The flaps have protrusions designed to reduce noise generation in the fluid flow.
1. An outflow valve for an aircraft to control a fluid flow between an inner environment and an outer environment of the aircraft, comprising:
a frame arranged to be disposed in an opening between the inner environment and the outer environment of the aircraft;
a first flap and a second flap contacting the first flap, the flaps being moveable within the frame for controlling the fluid flow through the opening between the inner environment and the other environment, each of the first and second flaps including an inner surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the outer environment in a close position of the outflow valve, the first and second flaps having a mutually contacting area between the inner surface of the first flap and the outer surface of the second flap for closing the outflow valve, the first flap including a plurality of first protrusions spaced-apart on the inner surface of the first flap, the second flap including a plurality of second protrusions spaced-apart on the inner surface of the second flap, the pluralities of first and second protrusions being spaced from the mutual contacting area of the flaps, each of the first protrusions of the first flap having a bottom portion on the inner surface of the first flap, each of the second protrusions of the second flap having a bottom portion on the inner surface of the second flap, each of the first and second protrusions having side surfaces arranged in a closed outline projecting from the bottom portion of each of the first and second protrusions and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment, the closed outlines of the side surfaces and the exposed top surfaces of the spaced-apart protrusions on the inner surfaces of the first and second flaps providing for creating overlapping, mutually disruptive vortices in the fluid flow to reduce noise, and the first and second protrusions being shaped differently.
2. The valve according to claim 1 , in which the closed outline of each of the first and second protrusions tapers from narrow to wide in the flow direction.
3. The valve according to claim 2 , in which the side surfaces of the first protrusions are arranged in a triangular outline, wherein a corner point of the outline defines a tip and the two other corner points define a base of the outline.
4. The valve according to claim 3 , in which the top surface of each of the first protrusions is formed as a section of a cylindrical surface, wherein the axis of the cylinder is essentially parallel to the outline and normal to the flow direction.
5. The valve according to claim 4 , in which the diameter of the cylinder that defines the top surface of the first protrusions and the length (l) of the edges extending from the tip to the base of the outline of the first protrusions have a ratio of at least 2 and no more than 6, preferably between 3.9 and 4.1.
6. The valve according to claim 3 , in which an edge between the top surface and one of the side surfaces at the base of the triangular outline of the first protrusions is formed as a flow break-away edge.
7. The valve according to claim 3 , in which the tip of the triangular outline of the first protrusions faces the flow direction.
8. The valve according to claim 3 , in which a length (b) of the base and a length (l) of the edges extending from the tip to the base of the outline of the first protrusions have a ratio b/l of at least 0.5 and no more than 0.9, preferably between 0.69 and 0.71.
9. The valve according to claim 3 , in which the height (h) of the first protrusions and the length (l) of the edges extending from the tip to the base of the outline of the first protrusions have a ratio h/l of at least 0 and no more than 0.5, preferably between 0.19 and 0.21.
10. The valve according to claim 2 , in which the top surface of each of the first protrusions has a concave configuration.
11. The valve according to claim 2 , in which the top surface of each of the first protrusions is in the form of an upward ramp in the flow direction.
12. The valve according to claim 2 , in which the side surfaces of the second protrusions on the inner surface of the second flap are arranged in trapezoidal outline, wherein a shorter side of the parallel sides of the outline define a tip and a longer one of the parallel sides of the outline define a base.
13. The valve according to claim 12 , in which the tip of the second protrusions is arranged upstream of the base.
14. The valve according to claim 12 , in which the edges forming the tip and the base of the second protrusions are arranged essentially transverse to the flow direction.
15. The valve according to claim 12 , in which an edge between the top surface and one of the side surfaces at the base of the trapezoidal outline of the second protrusions is formed as a flow break-away edge.
16. The valve according to claim 15 , in which the length (b 1 ) of the flow break-away edge and the length (l) of the edges extending from the tip to the base of the outline of the second protrusions have a ratio b 1 /l of at least 0.5 and no more than 0.9, preferably between 0.69 and 0.71.
17. The valve according to claim 12 , in which the length (b 2 ) of the base and the length (l) of the edges extending from the tip to the base of the outline of the second protrusions have a ratio b 2 /l of at least 0.7 and no more than 1.1, preferably between 0.89 and 0.91.
18. The valve according to claim 12 , in which the length (b 3 ) of the tip and the length (l) of the edges extending from the tip to the base of the outline of the second protrusions have a ratio b 3 /l of at least 0 and no more than 0.4, preferably between 0.09 and 0.11.
19. The valve according to claim 12 , in which the height (h) of the second protrusions and the length (l) of the edges extending from the tip to the base of the outline of the second protrusions have a ratio h/l of at least 0.1 and no more than 0.5, preferably between 0.29 and 0.31.
20. The valve according to claim 2 , in which the top surface of each of the second protrusions is configured as an upward ramp in the flow direction.
21. The valve according to claim 20 , in which the top surface of each of the second protrusions has a planar configuration.
22. The valve according to claim 1 , in which the first protrusions are arranged in one or more rows on the inner surface of the first flap extending transverse to the flow direction.
23. The valve according to claim 22 , in which the first protrusions are arranged in staggered rows transverse to the flow direction.
24. The valve according to claim 1 , further comprising a plurality of third protrusions spaced-apart on the outer surface of the second flap, each of the third protrusions of the second flap having a bottom portion on the outer surface of the second flap, side surfaces arranged in a closed outline projecting from the bottom portion of the third protrusions, and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment.
25. The valve according to claim 24 , in which the third protrusions are arranged in one or more rows on the outer surface of the second flap extending transverse to the flow direction.
26. The valve according to claim 24 , in which two or more rows of first protrusions are arranged on the inner surface of the first flap and two or more rows of the third protrusions are arranged on the outer surface of the second flap.
27. The valve according to claim 1 , in which the second protrusions are arranged in one or more rows on the inner surface of the second flap extending essentially transverse to the flow direction.
28. The valve according to claim 1 , in which the number of first protrusions exceeds the number of the second protrusions.
29. The valve according to claim 28 , in which the second protrusions have a larger volume than the first protrusions.
30. The valve according to claim 1 , in which the bottom portions of the first and second protrusions have rounded edges.
31. The valve according to claim 1 , in which the second flap has a rounded front edge providing a smooth connection to both the inner surface to the outer surface of the second flap facing the opening between the inner environment and the outer environment, the second protrusions are positioned on the inner surface of the second flap adjacent to the rounded front edge, and the first flap has a front edge that is not similarly rounded.
32. An outflow valve for an aircraft to control a fluid flow between an inner environment and an outer environment of the aircraft, comprising:
a frame arranged to be disposed in an opening between the inner environment and the outer environment of the aircraft;
a first flap and a second flap contacting the first flap, the flaps being moveable within the frame for controlling the fluid flow through the opening between the inner environment and the other environment,
each of the first and second flaps including an inner surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the outer environment in a close position of the outflow valve,
the first and second flaps having a mutually contacting area between the inner surface of the first flap and the outer surface of the second flap for closing the outflow valve,
the first flap including a plurality of first protrusions spaced-apart on the inner surface of the first flap,
the second flap including a plurality of second protrusions spaced-apart on the inner surface of the second flap,
the pluralities of first and second protrusions being spaced from the mutual contacting area of the flaps,
each of the first protrusions of the first flap having a bottom portion on the inner surface of the first flap,
each of the second protrusions of the second flap having a bottom portion on the inner surface of the second flap,
each of the first and second protrusions having side surfaces arranged in a closed outline projecting from the bottom portion of each of the first and second protrusions and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment,
the closed outlines of the side surfaces and the exposed top surfaces of the spaced-apart protrusions on the inner surfaces of the first and second flaps providing for creating overlapping, mutually disruptive vortices in the fluid flow to reduce noise,
the first protrusions being arranged in staggered rows transverse to the flow direction,
a plurality of third protrusions being spaced-apart on the outer surface of the second flap, and
each of the third protrusions of the second flap having a bottom portion on the outer surface of the second flap, side surfaces arranged in a closed outline projecting from the bottom portion of the third protrusions, and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment.
33. An outflow valve for an aircraft to control a fluid flow between an inner environment and an outer environment of the aircraft, comprising:
a frame arranged to be disposed in an opening between the inner environment and the outer environment of the aircraft;
a first flap and a second flap contacting the first flap, the flaps being moveable within the frame for controlling the fluid flow through the opening between the inner environment and the other environment,
each of the first and second flaps including an inner surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the inner environment and an outer surface oriented within the frame for facing the outer environment in a close position of the outflow valve,
the first and second flaps having a mutually contacting area between the inner surface of the first flap and the outer surface of the second flap for closing the outflow valve,
the first flap including a plurality of first protrusions spaced-apart on the inner surface of the first flap,
the second flap including a plurality of second protrusions spaced-apart on the inner surface of the second flap,
the pluralities of first and second protrusions being spaced from the mutual contacting area of the flaps,
each of the first protrusions of the first flap having a bottom portion on the inner surface of the first flap,
each of the second protrusions of the second flap having a bottom portion on the inner surface of the second flap,
each of the first and second protrusions having side surfaces arranged in a closed outline projecting from the bottom portion of each of the first and second protrusions and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment,
the closed outlines of the side surfaces and the exposed top surfaces of the spaced-apart protrusions on the inner surfaces of the first and second flaps providing for creating overlapping, mutually disruptive vortices in the fluid flow to reduce noise,
the first protrusions being arranged in staggered rows transverse to the flow direction,
a plurality of third protrusions being spaced-apart on the outer surface of the second flap,
each of the third protrusions of the second flap having a bottom portion on the outer surface of the second flap, side surfaces arranged in a closed outline projecting from the bottom portion of the third protrusions, and an exposed top surface projecting into the fluid flow through the opening between the inner environment and the outer environment, and
the number of first protrusions exceeding the number of the second protrusions.