Aero-acoustically dampened bleed valve
Aero-acoustically damped bleed valves are disclosed. An example variable bleed valve apparatus comprises a variable bleed valve door to actuate the variable bleed valve apparatus, and a variable bleed valve port including an upstream edge and a downstream edge, the VBV port to define a secondary flowpath, the VBV door to cover the VBV port in a closed position, and a vortex device at the upstream edge of the variable bleed valve port, the vortex device including a vorticity generating feature along the upstream edge of the variable bleed valve port.
1 . A variable bleed valve apparatus including a liner to define a wall of a bleed cavity, wherein the liner comprises:
a first porous facesheet located at a first end of the bleed cavity;
a second porous facesheet located at a second end of the bleed cavity;
a first resonant chamber and a second resonant chamber, each positioned between the first porous facesheet and the second porous facesheet; and
a partition, the partition to define an upper resonant chamber of the second resonant chamber and a lower resonant chamber of the second resonant chamber, wherein the upper resonant chamber is tuned to a different frequency than the lower resonant chamber.
2 . The variable bleed valve apparatus of claim 1 , wherein the partition is oriented at an interface angle.
3 . The variable bleed valve apparatus of claim 2 , wherein the interface angle is at least one of parallel, oblique, or perpendicular relative to the first porous facesheet or the second porous facesheet.
4 . The variable bleed valve apparatus of claim 1 , wherein the partition includes an aperture, the aperture to propagate an acoustic wave from the upper resonant chamber to the lower resonant chamber.
5 . The variable bleed valve apparatus of claim 4 , wherein the aperture includes a porous resistance septum.
6 . The variable bleed valve apparatus of claim 5 , wherein the porous resistance septum includes a porous sheet with at least one of: i) one or more holes, ii) a porous fabric layer, or iii) a porous wire mesh layer.
7 . A turbine engine comprising:
a first compressor;
a second compressor; and
a bleed port including a liner to define a wall of a bleed cavity, the liner including:
a first porous facesheet located at a first end of the bleed cavity;
a second porous facesheet located at a second end of the bleed cavity;
a first resonant chamber and a second resonant chamber, each positioned between the first porous facesheet and the second porous facesheet; and
a partition, the partition to define an upper resonant chamber of the second resonant chamber and a lower resonant chamber of the second resonant chamber, wherein the upper resonant chamber is tuned to a different frequency than the lower resonant chamber.
8 . The turbine engine of claim 7 , wherein the partition is oriented at an interface angle.
9 . The turbine engine of claim 8 , wherein the interface angle is at least one of parallel, oblique, or perpendicular relative to at least one of the first porous facesheet or the second porous facesheet.
10 . The turbine engine of claim 7 , wherein the partition includes an aperture, the aperture to propagate an acoustic wave from the upper resonant chamber to the lower resonant chamber.
11 . The turbine engine of claim 10 , wherein the aperture includes a porous resistance septum.
12 . The turbine engine of claim 11 , wherein the porous resistance septum includes a porous sheet with at least one of: i) one or more holes, ii) a porous fabric layer, or iii) a porous wire mesh layer.
13 . A liner of a bleed cavity, wherein the liner comprises:
a first porous facesheet located at a first end of the bleed cavity;
a second porous facesheet located at a second end of the bleed cavity;
a first resonant chamber and a second resonant chamber, each positioned between the first porous facesheet and the second porous facesheet; and
a partition, the partition to define an upper resonant chamber of the second resonant chamber and a lower resonant chamber of the second resonant chamber, wherein the upper resonant chamber is tuned to a different frequency than the lower resonant chamber.
14 . The liner of claim 13 , wherein the partition is oriented at an interface angle.
15 . The liner claim 14 , wherein the interface angle is at least one of parallel, oblique, or perpendicular relative to at least one of the first porous facesheet or the second porous facesheet.
16 . The liner of claim 13 , wherein the partition includes an aperture, the aperture to propagate an acoustic wave from the upper resonant chamber to the lower resonant chamber.
17 . The liner of claim 16 , wherein the aperture includes a porous resistance septum.
18 . The liner of claim 17 , wherein the porous resistance septum includes a porous sheet with at least one of: i) one or more holes, ii) a porous fabric layer, or iii) a porous wire mesh layer.