Inlet bleed diversion through rotating detonation rocket engine
A rocket-based combined cycle propulsion system comprising an air inlet and a centerbody extending along a center axis. The centerbody at least partially defines the air inlet. The system further includes a first propulsion system (e.g., a rotating detonation rocket engine, RDRE) and a second propulsion system (e.g., a scramjet) coupled with the first propulsion system. The system further includes an air bleed assembly including an inlet aperture formed in the centerbody, an outlet aperture positioned in the first propulsion system, and a duct fluidly connecting the inlet aperture and the outlet aperture.
1 . A rocket-based combined cycle propulsion system comprising:
an air inlet;
a centerbody extending along a center axis, wherein the centerbody at least partially defines the air inlet;
a first propulsion system;
a second propulsion system coupled with the first propulsion system; and
an air bleed assembly including an inlet aperture formed in the centerbody, an outlet aperture positioned in the first propulsion system, and a duct fluidly connecting the inlet aperture and the outlet aperture; and
wherein the first propulsion system includes a rotating detonation rocket engine (RDRE); and wherein the RDRE is positioned between the air inlet and a flameholder of the second propulsion system.
2 . The system of claim 1 , further comprising an outer cowl, wherein the centerbody is at least partially positioned within the outer cowl, and wherein the outer cowl at least partially defines the air inlet.
3 . The system of claim 2 , wherein the inlet aperture is positioned on the centerbody such that the inlet aperture is aligned with a leading end of the outer cowl along the center axis.
4 . The system of claim 1 , wherein the inlet aperture is positioned at the air inlet.
5 . The system of claim 1 , wherein the centerbody includes an inlet cone portion extending from the air inlet, and wherein the inlet aperture is positioned on the inlet cone portion.
6 . The system of claim 1 , the inlet aperture is one of a plurality of inlet apertures formed in the centerbody, wherein the duct fluidly connects each of the plurality of inlet apertures to the outlet aperture.
7 . The system of claim 6 , wherein each of the plurality of inlet apertures is positioned at a first axial location along the center axis.
8 . The system of claim 6 , wherein one of the plurality of inlet apertures is positioned at a first axial location along the center axis; and another one of the plurality of inlet apertures is positioned at a second axial location axially along the center axis.
9 . The system of claim 6 , wherein the air bleed assembly further includes a plenum and a plurality of bores extending between the plurality of inlet apertures and the plenum.
10 . The system of claim 9 , wherein each of the plurality of bores includes a diameter and a length extending between the inlet aperture and the plenum; wherein a ratio of the length to the diameter is within a range of 2-3.
11 . The system of claim 1 , wherein the air bleed assembly further includes one or more channels extending between the inlet aperture and the duct.
12 . The system of claim 11 , wherein the one or more channels are arcuate.
13 . The system of claim 1 , wherein the duct is aligned with the center axis.
14 . The system of claim 1 , wherein the RDRE includes an annulus defining an annulus axis, wherein the annulus axis is parallel with the center axis.
15 . The system of claim 14 , wherein the annulus includes an inner wall and an outer wall, and wherein the inner wall and the outer wall define a detonation chamber therebetween.
16 . The system of claim 15 , wherein the inner wall at least partially defines a body, and wherein the outlet aperture is positioned on an axial end surface of the body.
17 . The system of claim 15 , wherein the RDRE includes a fuel source, an oxidizer source, and a plurality of injectors positioned around the detonation chamber.
18 . The system of claim 1 , wherein the RDRE is oriented such that, during operation of the rocket-based combined cycle propulsion system, exhaust from the RDRE will affect the air prior to the air being used in combustion by the second propulsion system.
19 . The system of claim 18 , wherein said RDRE increases a temperature and a pressure of said air prior to said air being received by said second propulsion system.
20 . The system of claim 1 , wherein the second propulsion system is a ramjet or a scramjet.
21 . The system of claim 1 , wherein a mass flow through the air bleed assembly is within a range of 0%-5% of a total mass flow through the rocket-based combined cycle propulsion system.
22 . The system of claim 1 , wherein a suction present at the inlet aperture is at least partially based on a throttle of the first propulsion system.
23 . The system of claim 22 , wherein suction at the inlet aperture remains when the first propulsion system is off.
24 . The system of claim 1 , wherein air passing through the bleed assembly cools the first propulsion system.
25 . The system of claim 1 , further comprising a regulator positioned at the inlet aperture or in the duct, wherein the regulator is configured to control a mass flow rate through the inlet aperture.
26 . The system of claim 25 , wherein the regulator is configured to actively adjust the mass flow rate through the inlet aperture.
27 . The system of claim 1 , wherein the air bleed assembly further comprises a valve and a secondary airflow circuit; wherein control of the valve select whether air flowing through the air bleed assembly flows to the first propulsion system or to the secondary airflow circuit.