Hypersonic inlet systems and methods
View Patent ↗Hypersonic inlet systems and methods are disclosed. In one embodiment, an inlet for an airbreathing propulsion system includes an inboard surface at least partially shaped to conform to a plurality of streamline-traces of a design flowfield approaching an aperture, an outboard surface spaced apart from the inboard surface, an upper surface extending between the inboard and outboard surfaces, and a lower surface extending between the inboard and outboard surfaces, wherein leading edges of the inboard, outboard, upper, and lower surfaces cooperatively define the aperture.
1. An inlet assembly for an airbreathing propulsion system, comprising:
a pair of inlets comprising separate apertures defined by an upper surface leading edge, a lower surface leading edge, and a centerbody disposed between the inlets, wherein the centerbody is at least partially shaped to conform to a plurality of streamline-traces of a design flowfield downstream from the apertures, wherein at least one of the pair of inlets comprises:
a low speed inlet flap configured to selectively open and close a low speed diffuser duct connected to a turbojet engine, wherein the low speed inlet flap rotates outwardly from the centerbody, from a first inboard position in which the low speed inlet flap closes the low speed diffuser duct, to a second outboard position in which the low speed inlet flap opens the low speed diffuser duct;
a high speed inlet flap positioned along an outboard edge and configured to selectively deflect toward the centerbody to control airflow entering a high-speed diffuser duct connected to a dual mode ramjet/scramjet engine.
2. The inlet assembly of claim 1 , wherein the low speed inlet flap rotates into an airflow in the inlet to open the low speed diffuser duct.
3. The inlet assembly of claim 1 , wherein the high speed inlet flap is positioned against a fixed cowl and rotates inwardly toward the centerbody from a first position in which the high speed inlet flap is retracted to a second position in which the high speed inlet flap regulates an airflow into the high speed diffuser duct.
4. The inlet assembly of claim 1 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion pivots independently of the first portion to control an internal area distribution within a compression zone.
5. The inlet assembly of claim 1 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion retracts independently of the first portion to selectively open and close a bypass channel.
6. The inlet assembly of claim 1 , wherein the centerbody defines:
at least one variable geometry region proximate a throat region leading to the low speed diffuser duct; and
at least one bleed region.
7. The inlet assembly of claim 6 , wherein the variable geometry regions and bleed regions enable control of an expansion rate of a subsonic flow entering the high speed diffuser duct.
8. An airbreathing propulsion system comprising:
a pair of inlets comprising separate apertures defined by an upper surface leading edge, a lower surface leading edge, and a centerbody disposed between the inlets, wherein the centerbody is at least partially shaped to conform to a plurality of streamline-traces of a design flowfield downstream from the apertures, wherein at least one of the pair of inlets comprises:
a low speed inlet flap configured to selectively open and close a low speed diffuser duct, wherein the low speed inlet flap rotates outwardly form the centerbody, from a first inboard position in which the low speed inlet flap closes the low speed diffuser duct, to a second outboard position in which the low speed inlet flap opens the low speed diffuser duct;
a high speed inlet flap positioned along an outboard edge and configured to selectively deflect toward the centerbody to control airflow entering a high-speed diffuser duct;
a turbojet engine connected to the low speed diffuser duct; and
a dual mode ramjet/scramjet engine connected to the high speed diffuser duct.
9. The airbreathing propulsion system of claim 8 , wherein the low speed inlet flap rotates into an airflow in the inlet to open the low speed diffuser duct.
10. The airbreathing propulsion system of claim 8 , wherein the high speed inlet flap is positioned against a fixed cowl and rotates inwardly toward the centerbody from a first position in which the high speed inlet flap is retracted to a second position in which the high speed inlet flap regulates an airflow into the high speed diffuser duct.
11. The airbreathing propulsion system of claim 8 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion pivots independently of the first portion to control an internal area distribution within a compression zone.
12. The airbreathing propulsion system of claim 8 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion retracts independently of the first portion to selectively open and close a bypass channel.
13. The airbreathing propulsion system of claim 8 , wherein the centerbody defines:
at least one variable geometry region proximate a throat region leading to the low speed diffuser duct; and
at least one bleed region.
14. The airbreathing propulsion system of claim 13 , wherein the variable geometry regions and bleed regions enable control of an expansion rate of a flow entering the high speed diffuser duct.
15. A method to operate an airbreathing propulsion system, comprising:
receiving an airflow into a pair of inlets comprising separate apertures defined by an upper surface leading edge, a lower surface leading edge, and a centerbody disposed between the inlets, wherein the centerbody is at least partially shaped to conform to a plurality of streamline-traces of a design flowfield downstream from the apertures;
activating a low speed inlet flap configured to selectively open and close a low speed diffuser duct connected to a turbojet engine, wherein the low speed inlet flap rotates outwardly, from the centerbody from a first inboard position in which the low speed inlet flap closes the low speed diffuser duct, to a second outboard position in which the low speed inlet flap opens the low speed diffuser duct; and
activating a high speed inlet flap positioned along an outboard edge and configured to selectively deflect toward the centerbody to control airflow entering a high-speed diffuser duct connected to a dual mode ramjet/scramjet engine.
16. The method of claim 15 , wherein the low speed inlet flap rotates into an airflow in the inlet to open the low speed diffuser duct.
17. The method of claim 15 , wherein the high speed inlet flap is positioned against a fixed cowl and rotates inwardly toward the centerbody from a first position in which the high speed inlet flap is retracted to a second position in which the high speed inlet flap regulates an airflow into the high speed diffuser duct.
18. The method of claim 15 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion pivots independently of the first portion to control an internal area distribution within a compression zone.
19. The method of claim 15 , wherein:
the high speed inlet flap has a first portion and a second portion; and
the second portion retracts independently of the first portion to selectively open and close a bypass channel.