Compact bleed valve assemblies
Compact bleed valve assemblies are disclosed. An example turbine engine comprises a rotor blade having an axial chord (C) measured at a tip of the rotor blade, and a variable bleed valve (VBV) including a VBV port defining a bleed flowpath and an exit angle (β exit ) for bleed air exiting the VBV port, the VBV port including a forward entrance edge and an aft exit edge and a first length (LA) therebetween, and a VBV door corresponding to the VBV port, the VBV door to generate a bleed cavity having a bleed cavity area (BA) in the VBV port when the VBV is in a closed position, the VBV door to move between an open position and the closed position at a rotation angle (Δθ), the VBV door to extend a distance (LA act ) beyond the first length (LA), wherein L A + L A a c t C - 2 * ( B V I P + 0 . 1 5 ) - 1 . 3 5 ≤ - 0.8 , and wherein B V I P = 0 . 1 5 * B A C 2 + 0 . 8 5 * Δ θ + β e x i t 2 π .
1. A turbine engine comprising:
a rotor blade having an axial chord (C) measured at a tip of the rotor blade; and
a variable bleed valve (VBV) including:
a VBV port defining a bleed flowpath and an exit angle (β exit ) for bleed air exiting the VBV port, the VBV port including a forward entrance edge and an aft exit edge and a first length (LA) therebetween, the rotor blade to correspond to a first rotor blade positioned upstream of the forward entrance edge; and
a VBV door corresponding to the VBV port, the VBV door to generate a bleed cavity having a bleed cavity area (BA) in the VBV port when the VBV is in a closed position, the VBV door to move between an open position and the closed position at a rotation angle (Δθ), the VBV door to extend a distance (LA act ) beyond the first length (LA);
wherein the VBV is defined by an ineffectiveness parameter (BVIP);
wherein
L
A
+
L
A
act
C
-
2
*
(
BVIP
+
0
.
1
5
)
-
1
.
3
5
≤
-
0.8
;
and
wherein
BVIP
=
0.
1
5
*
B
A
C
2
+
0
.
8
5
*
Δ
θ
+
β
exit
2
π
.
2. The turbine engine of claim 1 , wherein (LA+LA act )/C is at least 0.465 and less than or equal to 27.9.
3. The turbine engine of claim 1 , wherein the BVIP is at least 0 and less than or equal to 0.830.
4. The turbine engine of claim 1 , wherein the VBV door is flush with a main flow path in the closed position to limit the bleed cavity area (BA);
wherein the bleed cavity area (BA) is zero; and
wherein a ratio BA/C 2 is zero.
5. The turbine engine of claim 1 , wherein Δθ/2π is at least −0.25 and is less than or equal to 0.25, and wherein Δθ/2π is not equal to 0.
6. The turbine engine of claim 1 , wherein β exit /2π is at least −0.375 and less than or equal to 0.375.
7. The turbine engine of claim 1 , wherein the VBV door slides between the open position and the closed position, and wherein Δθ/2π is 0.
8. The turbine engine of claim 7 , wherein BA/C 2 is greater than zero.
9. The turbine engine of claim 1 , wherein VBV door pivots about a pivot point to move between the open position and the closed position, and wherein a ratio BA/C 2 is 0.
10. The turbine engine of claim 9 , wherein the pivot point is within the VBV port, and wherein Δθ/2π is less than 0.
11. The turbine engine of claim 9 , wherein the pivot point is at the forward entrance edge, and wherein Δθ/2π is greater than 0.
12. The turbine engine of claim 1 , wherein
L
A
+
L
A
act
C
-
2
*
(
BVIP
+
0
.
1
5
)
-
1
.
3
5
≤
-
1.8
.
13. The turbine engine of claim 12 , wherein (LA+LA act )/C is at least 0.465 and less than or equal to 22.06.
14. The turbine engine of claim 12 , wherein the BVIP is at least 0 and less than or equal to 0.661.
15. The turbine engine of claim 12 , wherein Δθ/2π is at least −0.1389 and less than or equal to 0.1361.
16. The turbine engine of claim 12 , wherein β exit /2π is at least −0.25 and less than or equal to 0.25.
17. A turbine engine comprising:
at least one rotor blade having a blade tip, the blade tip having an axial chord (C); and
a variable bleed valve (VBV) including:
a VBV port defining an exit angle (β exit ) for air exiting the VBV port, the VBV port including an entrance lip and an exit lip, the VBV port having an axial port length (LA) defined by a first distance between the entrance lip and the exit lip, the at least one rotor blade positioned forward of the entrance lip; and
a VBV door corresponding to the VBV port, the VBV door to generate a bleed cavity having an area (BA) in the VBV port when the VBV is in a closed position, the VBV door to move between an open position and the closed position at a rotation angle (Δθ), the VBV door to extend a second distance (LA act ) beyond the axial port length (LA);
wherein the VBV is defined by an ineffectiveness parameter (BVIP);
wherein
BVIP
=
0
.
1
5
*
B
A
C
2
+
0
.
8
5
*
Δ
θ
+
β
exit
2
π
;
and
wherein
L
A
+
L
A
act
C
-
2
*
(
BVIP
+
0
.
1
5
)
-
1
.
3
5
≤
-
0
.
8
.
18. The turbine engine of claim 17 , wherein
L
A
+
L
A
act
C
is greater than or equal to 0.465 and less than or equal to 27.9, and wherein the BVIP is at least 0 and less than or equal to 0.830.
19. The turbine engine claim 17 , wherein Δθ/2π is greater than or equal to −0.25 and less than or equal to 0.25, and wherein βexit/2π is at least −0.375 and less than 0.375.
20. The turbine engine of claim 17 , wherein
L
A
+
L
A
act
C
-
2
*
(
BVIP
+
0
.
1
5
)
-
1
.
3
5
≤
-
1.8
.