Exhaust assembly forming a horizontal propulsion gas elbow in an aircraft
View Patent ↗A propulsion gas exhaust assembly in an aircraft propelled by hot gases produced along the axis of the latter by a gas generator is disclosed. The exhaust assembly includes a duct which forms a vertical elbow and a nozzle.
1. A propulsion gas exhaust assembly, in an aircraft propelled by hot gases produced by a gas generator along a center axis of the gas generator, comprising:
a duct; and
a nozzle,
wherein the center axis of the gas generator passes through an inlet of the duct and the nozzle,
wherein said duct includes a vertical elbow defined by a first portion which guides the gas flow in a radial direction away from the axis of the gas generator and a second portion downstream of the first portion which guides the gas flow in a radial direction toward the center axis of the gas generator, downstream of the elbow the gas flow being returned to the center axis of the gas generator,
wherein the axis of the nozzle is parallel and coaxial to the axis of the gas generator and the axis of the inlet of the duct, and
wherein elements disposed inside the duct upstream of the elbow are not visible when the assembly is viewed directly into the nozzle.
2. The assembly as claimed in claim 1 , wherein the gas generator is a turbojet.
3. The assembly as claimed in claim 1 , wherein a cross section of the duct is elongate in shape in the crosswise direction.
4. The assembly as claimed in claim 1 , wherein the duct comprises an entrance plane and the nozzle comprises a throat plane, the distance between the entrance plane and the throat plane is a length L channel , and a plane of the elbow, corresponding to a maximum vertical deviation of the elbow from the center axis of the gas generator, is situated at a distance from the entrance plane L elbow such that the ratio L elbow /L channel lies between 0.5 and 0.7.
5. The assembly as claimed in claim 4 , wherein a ratio H int /H ext of a height H int of an internal wall of the elbow and a height H ext of the external wall of the elbow relative to the axis of the gas flow, at the maximum vertical deviation, is less than ½.
6. The assembly as claimed in claim 5 , wherein a ratio H ext /L channel is approximately ⅓.
7. The assembly as claimed in claim 1 , wherein the duct comprises successively a first cylindrical duct element, a second duct element, first and second third duct elements, each of the first and second third duct elements open into a first half-nozzle and a second half-nozzle, respectively.
8. The assembly as claimed in claim 7 , wherein a main propulsion gas flow is divided into a first and a second flow for an ejection into the first and the second half-nozzle, and the assembly further comprises at least one of the following two controlling means: a means of distributing the main flow into each of the two half-nozzles and a means of orienting the thrust vector produced by each of the two half-nozzles.
9. The assembly as claimed in claim 8 , wherein said two means are fluid injection or mechanical.
10. The assembly as claimed claim 7 , wherein said half-nozzles are placed for a yaw orientation of the thrust vector.
11. The assembly as claimed in claim 7 , wherein said half-nozzles are placed for a pitch control.
12. The assembly as claimed in claim 8 , further comprising first and second pairs of fluid injectors, the first pair for yaw orientation, and the second pair for pitch orientation.
13. The assembly as claimed in claim 8 , wherein the means for controlling the distribution of the flows comprises means for fluid injection at the throat of each of the first and second half-nozzles.
14. The assembly as claimed in claim 9 , wherein the gas generator is a turbojet, and the fluid injection means are supplied by air tapped from a compressor of the generator.
15. A method of operating the exhaust assembly as claimed in claim 14 comprising tapping air continuously from the compressor of the generator.
16. The assembly as claimed in claim 7 , wherein the main flow is generated by two gas generators, and the assembly further comprises a means of orienting a thrust vector produced by each of the first and second two half-nozzles.
17. A turbomachine comprising an exhaust assembly as claimed in claim 1 .
18. The assembly as claimed in claim 14 , wherein the fluid injection means includes a first fluid injector disposed on a wall at a throat and a second fluid injector disposed on a wall of divergence.