Variable geometry inlet design for scram jet engine
View Patent ↗The present invention relates to an improved variable geometry inlet for a scram jet engine having at least one combustor module. The variable geometry inlet comprises each combustor module having two sidewalls. Each of the sidewalls has a central portion with a thickness and a tapered profile forward of the central portion. The tapered profile terminates in a sharp leading edge. The variable geometry inlet further comprises each module having a lower wall and a movable cowl flap positioned forward of the lower wall. The movable cowl flap has a leading edge and the leading edges of the sidewalls intersect the leading edge of the cowl flap.
1. A variable geometry inlet for a scram jet engine having at least one combustor module, said inlet comprising:
each said combustor module having two sidewalls;
each said sidewall having a central portion with a thickness and a tapered profile forward of said central portion which terminates in a sharp leading edge;
each said module having a lower wall and a movable cowl flap positioned forward of said lower wall; and
said movable cowl flap having a leading edge.
2. A variable geometry inlet according to claim 1 , further comprising:
said leading edges of said sidewalls intersecting said cowl flap leading edge.
3. A variable geometry inlet according to claim 2 , further comprising at least one of said sidewalls having a leading edge extending in front of the leading edge of said cowl flap.
4. A variable geometry inlet according to claim 2 , further comprising means for actuating said cowl flap.
5. A variable geometry inlet according to claim 2 , wherein each said sidewall central portion has a thickness sufficient to house at least one component for actuating said cowl flap.
6. A variable geometry inlet according to claim 2 , wherein said cowl flap has a trailing edge and is flared from said trailing edge to said leading edge to follow said sidewall profile.
7. A variable geometry inlet for a scram jet engine having a plurality of combustor modules, said inlet comprising:
a pair of outboard sidewalls and at least one interior sidewall defining said combustor modules; and
each of said outboard sidewalls and each said interior sidewall having a central portion with a thickness and a tapered profile forward of said central portion which terminates in a sharp leading edge.
8. A variable geometry inlet according to claim 7 , further comprising:
each said module having a lower wall and a movable cowl flap positioned forward of said lower wall;
each said cowl flap being positioned between two of said sidewalls and having a leading edge; and
said leading edges of said two sidewalls each intersecting said cowl flap leading edge.
9. A variable geometry inlet according to claim 8 , further comprising:
each of said outboard sidewalls having a leading edge located forward of the leading edge of each said movable cowl flap.
10. A variable geometry inlet according to claim 8 , wherein each said cowl flap has a trailing edge and flared edges extending from said trailing edge to said leading edge; and
each said flared edges mimicking the tapered profile of an adjacent one of said sidewalls.
11. A variable geometry inlet according to claim 10 , further comprising a constant gap between each said flared edge and said adjacent one of said sidewalls.
12. A variable geometry inlet according to claim 7 , wherein each said module has a common width and an equal adjustable flow.
13. A variable geometry inlet according to claim 7 , wherein each said module has an equal capture width.
14. A variable geometry inlet according to claim 8 , wherein said cowl flaps rotate about a common hinge line.
15. A variable geometry inlet according to claim 14 , further comprising means for actuating each of said cowl flaps.
16. A variable geometry inlet according to claim 15 , wherein said actuation means includes a crank arm attached to each of said flaps and a plurality of actuators for operating each said crank arm.
17. A variable geometry inlet according to claim 16 , wherein said actuation means further includes a plurality of hinge pins, bearings, and means for mechanically attaching said hinge pins and bearings to a static structure.
18. A variable geometry inlet according to claim 17 , wherein said mechanical attaching means comprises at least one support block.
19. A variable geometry inlet according to claim 7 , further comprising a swept extension added to each said outboard sidewall leading edge to reduce local spillage.
20. A variable geometry inlet for a scram jet engine having a plurality of combustor modules, said inlet comprising:
a pair of outboard sidewalls and at least one interior sidewall defining said combustor modules;
each of said outboard sidewalls and each said interior sidewall having a central portion with a thickness and a tapered profile forward of said central portion which terminates in a sharp leading edge; and
said tapered profile for each said outboard sidewall including an outer surface having a first wall portion extending in a first plane and a second wall portion tapered inwardly and an inner surface having a third wall portion extending substantially parallel to said first wall portion and a fourth wall portion tapering outwardly.