US3432100A - Ejecting nozzle for propellers provided with a plurality of driving streams and,more particularly,two driving streams - Google Patents

Description

March 11, 1969 HARDY ETAL 3,432,100

EJEC'IING NOZZLE FOR PROPELLERS PROVIDED WITH A PLURALIIY 0F DRIVING STREAMS AND, MORE PARTICULARLY, TWO DRIVING STREAMS Filed April 20, 1967 Sheet of 5 u Quiz, Swain wcu'dw March 11. 1969 J. M. HARDY ETAL 3,432,100

EJECTING NOZZLE FOR PROPELLERS PROVIDED WITH A PLURALITY 0F DRIVING STREAMS AND, MORE PARTICULARLY, TWO DRIVING STREAMS Filed April 20, 1967 Sheet 2 520.12, w -4- w n J. M. HARDY ETAL LE F0 March 11, 1969 EJECTING NOZZ R PROPELLERS PROVIDED WIT PLURALITY 0F DRIVING STREAMS AND, MORE PARTICULARLY, TWO DRIVING STREAMS Filed April 20, I967 Sheet rdltrllrlilllldll o It!!! I, Blair/$042.

United States Patent 3,432,100 EJECTING NOZZLE FOR PROPELLERS PROVIDED WITH A PLURALITY 0F DRIVING STREAMS AND, MORE PARTICULARLY, TWO DRIVING STREAMS Jean Marie Hardy, Esbly,

and Henry Marie Andre Rene Lacombe, Bois-le-Roi,

France, assignors to Societe Nationale dEtude et de Construction de Moteurs dAviation, Paris, France, a company of France Filed Apr. 20, 1967, Ser. No. 632,438 Claims priority, application France, Apr. 20, 1966,

s U.S. Cl. 239-1213 4 Claims Int. Cl. B64d 33/04; B64c 15/04 ABSTRACT OF THE DISCLOSURE Since the conditions of flight of aircrafts increase and the requirements as to performances are more and more drastic, there is a growing tendency to resort to propelling engines operating in accordance with a compound thermodynamic cycle with a plurality of driving streams.

We may mention by way of example turbojet engines operating with a double stream of a conventional type with or without a fan and incorporating heating means for one or both streams and also the associated simple or double stream ram and turbojet engines.

In order to obtain the best results with such,propc1ling groups, it has been found necessary to design' more and more improved ejecting nozzles. Our invention has for its object an ejecting nozzle for propelling engines operating with several driving streams and more particularly with two driving streams in which the inner stream may be stopped whenever required and which suits a large range of flying conditions between subsonic andhigh supersonic speeds.

According to the invention, a nozzle for jet engines operating with two driving streams includes a central streamlined body, movable or otherwise, an inner streamlined annular channel adapted to be closed by an annular series of pivoting flaps so as to adjust as required the ejection of the inner driving stream and an outer annular channel bounded by an outer casing provided at its downstream end with an annular series of angularly adjustable flaps which allow controlling the ejection of the outer driving stream.

The selection of the relative longitudinal position of the annular series of flaps adjusting the inner driving stream and the outer driving stream depends on the case considered. The annular series of flaps adjusting the outer driving stream may be located for instance either com- .pletely on the upstream side of the annular series of flaps adjusting the inner driving stream or else completely on the downstream side of the latter.

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In the first case, the annular series of flaps adjusting the outer driving stream controls solely the ejection of the latter. It is then possible to resort to the advantages provided by the outlines of the flaps adjusting said outer driving stream by the fairing of the inner annular chan nel, by the flaps adjusting the inner driving stream and by the central body with a view to obtaining a high grade ejection for all conditions of flight. It is in particular possible to form convergent and divergent channels when the gas pressure in the ejection chamber is low. In the second case, the outer and inner driving streams open into a common channel and the simultaneous ejection along the central body is performed in registry with the free ends of the outer flaps adjusting the outer driving stream. As in the preceding case, the outlines of the diflerent parts of the nozzle may be caused to match the conditions of flight. It is possible to associate with the nozzle free or controlled terminal flaps along which the expansion of the gases may continue, said terminal flaps opening all the more when the rate of expansion is higher.

Similarly, it is possible to design a nozzle including as many annular channels and annular series of adjusting flaps arranged coaxially with reference to a central streamlined body as there are driving streams, each of said series controlling possibly up to a closed condition the ejection of the stream out of the corresponding channel, the relative location of said annular series depending on the particular problem to be solved.

The following description and accompanying diagrammatic drawings given by way of example and by no means in a binding sense will allow understanding how the invention can be executed, the features appearing in the drawings and in the specification forming obviously part of the invention. In said drawings:

FIG. 1 is a diagrammatic axial sectional view of our improved nozzle wherein the flaps adjusting the outer driving stream are located upstream with reference to the flaps adjusting the inner driving stream.

FIGS. 2 and 3 are diagrammatic views of a half of a nozzle similar to that illustrated in FIG. 1, associated with a propelling system comprising a ramjet and a turbojet operating with a single stream, said figures corresponding to two different conditions of flight.

FIG. 4 is a diagrammatic axial sectional view of a further embodiment of our improved nozzle according to which the flaps adjusting the outer driving stream are located on the downstream side of the flaps adjusting the inner driving stream.

FIGS. 5 to 7 are diagrammatic views of one half of a nozzle of the type illustrated in FIG. 4 and used in combination with a propelling system comprising a ramjet and a turbo-jet operating with a double stream, said figures illustrated three diiferent conditions of flight.

Turning to FIG. 1, there is illustrated thereon a nozzle according to our invention, wherein the flaps adjusting the outer driving stream are located on the upstream side of the flaps adjusting the inner driving stream. Said nozzle includes a central stationary streamlined body 1 surrounded by an inner annular channel 2 extending between said body and an intermediate streamlined wall 3 provided at its downstream end with an annular series of flaps 4 adjustable through the agency of jacks 5 and adapted to completely close the channel 2 when turned back over the body 1, while an outer annular channel 6 extends between said wall 3 and the outer wall 7 of the nozzle which carries at its downstream end an annular series of flaps 8 the angular setting of which is adjusted under the action of the jacks 9. The arrangement may furthermore be provided with a cooling channel 10 feeding ventilating air and extending between the outer wall '7 of the nozzle and the wall 11 of the aircraft cellule, while flaps 12 are provided along the outer boundary layer and terminal streamlined picking up flaps 13 whether free or controlled are pivotally secured at 14 to the end of the wall of the aircraft cellule. The central body 1 includes an upstream section 1a of an increasing cross-section merging in registry with its maximum cross-section 1b with a downstream section 10 of a gradually decreasing cross-section.

The outer driving stream may be supplied as illustrated in FIGS. 2 and 3 by an outer annular ramjet 15 housed within the outer channel 6 and which is ignited for high speed or accelerated flight whereas the inner driving stream is produced by a central turbojet 16 opening into the inner channel 2 and which is inoperative when the aircraft flies at high speeds, so that it serves solely for flights at low and medium speeds.

The operation of said nozzle is as follows:

During flight at a low or mean speed, that is in the case of FIG. 2 when the ramjet 15 is not ignited, the pressure of the gases produced by the central turbojet 16 inside the inner channel 2 may be much higher than that of the air flowing in the outer channel 6, that is the air entering the engine through the air input 17 without passing through the turbo-jet. In such a case, it is of interest to expand substantially the inner driving stream before it converges with the air in the outer channel. This is obtained by directing the flaps 4 in a manner such as to make them form with the streamlined central body 1 a primary convergent and divergent channel, as illustrated for the flaps drawn in the lower half of FIG. 1. The auxiliary channel 18 may obviously serve for exhausting air under low energy conditions which air passes out of the cooling channel 10 or out of the outer boundary layer along the flaps 12. When flying at a high speed, that is in the case of FIG. 3 with the turbo-jet 16 in an inoperative condition, the pressure of the gases produced by the ramjet 15 is generally much higher than the ambient pressure in the area of the ejecting means and it is possible again in this case to produce a convergent and divergent channel which ensures a proper ejection of the gases. Under such flying conditions, the flaps 4, 8 and 12 occupy the positions illustrated in the upper half of FIG. 1, that is the inner channel 2 is closed by the flap 4.

Lastly, in all cases and chiefly when accelerating with the turbo-jet and the ramjet both in operation, the inner and outer driving streams may be controlled independently by means of the flaps 4 and 8.

FIG. 4 illustrates a further nozzle according to our invention. Said nozzle distinguishes from the preceding nozzle solely through the fact that the flaps adjusting the outer driving stream are located on the downstream side of the flaps adjusting the inner driving stream instead of being located on the upstream side. Said arrangement is of particular interest in the case where the inner stream is not stopped and pressures of the gases produced by the propelling engine inside the inner and outer channels are of similar magnitudes; this is the case for instance when the propelling system includes a turbo-jet operating with a double stream and is equipped or otherwise with means for heating either of said streams, said turbo-jet delivering its primary stream into the inner channel 2 and its secondary stream into the annular channel 6. The operation of the flaps 4 allows then adjusting the relative outputs of the two sreams and supplies thus a further parameter for adjusting the turbo-jet operation. The flaps 8 serve then on the one hand for controlling the total throughput of the ejected gases and on the other hand for forming a convergent and divergent channel with the central body 1, if it is considered preferable to produce a preliminary expansion of the entire driving stream before its ejection. By way of example, the upper half of FIG. 4 illustrates the setting of the different flaps during flight at a reduced speed, while the lower half of said figure shows the setting in position of said flaps during flight at a high speed.

FIGS. 5 to 7 illustrate by way of example and for various speeds of flight the application of a nozzle of the type illustrated in FIG. 4 to a propelling engine including a ramjet and a turbo-jet operating with a double stream the secondary stream of which may be re-heated by means of the burners of the ramjet 15 when the latter is not operative.

FIG. 5 shows thus the propelling engine and the nozzle operating under normal supersonic flying speeds. The turbo-jet is extinguished and only the ramjet ensures the propulsion of the aircraft. The flaps 4, 8 and 13 assume the positions shown in the lower half of FIG. 4, that is the inner channel 2 is closed and the flaps 8 and 13 form a convergent and divergent channel with the central body 1. Furthermore, auxiliary flaps 19 and 20 close respectively the annular channel 21, through which flows the secondary stream of the turbojet entering the outer channel 6 on the upstream side of the burner of the ramjet 15 and the annular channel 22 feeding air to the low pressure compressor 23 of the turbo-jet.

The air entering thus the propelling engine through the air input 17 flows through the outer channel 6 after passing over the burners 15 of the ramjet along the path illustrated by the arrows.

FIG. 6 illustrates the whole propelling engine together with the nozzle when subjected to acceleration. The PI pelling engine operates then as a turbo-jet with a double stream, the secondary stream being heated by the b rn rs 15. The flaps 4, 8 and 13 are in a position similar to that illustrated in the upper half of FIG. 4. The auxiliary flaps 19 and 20 close the upstream section of the outer channel 6, so that all the air entering at 17 is directed towards the low pressure compressor 23 of the turbo-jet. At the output end of the latter, the stream of air is conventionally subdivided into a primary stream and into a secondary stream. The primary stream, after passing through the high pressure compressor 24, the combustion chamber the group of turbines 26 and the inner channel 2 converges on the downstream side of the flaps 4 with the secondary stream which flows out through the channels 21 and 6 and is heated by the burners 15.

FIG. 7 illustrates similarly the propelling System and the nozzle under sub-sonic flight conditions. Said figure differs from the preceding one only through the fact that the burners 15 are extinguished. The propelling system operates in this case as a double stream turbo-jet.

In all cases, the operation of the different flaps in the nozzle allows obtaining an operation of the propelling engine which matches perfectly the conditions of flight.

Obviously, the invention is not limited to the embodiments which have been explicitly described but it covers also those which may be obtained b resorting to equivalent technical means. In particular, the annular series of flaps may be replaced by equivalent means such as ferrules adapted to be longitudinally shifted with reference to the central body.

What we claim is:

1. A nozzle for propulsive jet systems having two highenergy driving streams, comprising a central streamlined body, an intermediate wall defining with said central body an inner annular streamlined channel adapted to be flowed by a first driving stream, an annular series of flaps pivotally mounted at the downstream end of said intermediate wall and angularly adjustable for controlling the ejection of said first driving stream, down to a position where said flaps close said inner channel, an outer wall defining with said intermediate Wall an annular outer channel adapted to be flowed by a second driving stream, another annular series of flaps pivotally mounted at the downstream end of said outer wall and angularly adjustable for controlling the ejection of said second driving References Cited stream.

2. A nozzle as claimed in claim 1, which further com- UNITED STATES PATENTS prises wall mean surrounding said outer wall and defining 3,057,150 10/1962 Horgfm 239-1273 therewith an annular channel adapted to be flowed by a 3,062,003 11/1962 Haml'lton 239 127-3 cooling air stream. 5 3,262,264 7/1966 Gardlner et al 239127.3

3. A nozzle as claimed in claim 2, wherein said wall 3,302,889 2/1967 sabato 239 265-29 means OmPnse bIOW'm'dOOY flaps- EVERETT W. KIRBY, Primary Examiner.

4. A nozzle as claimed in claim 2, which comprises terminal flaps pivotally mounted at the downstream end of said wall means.

US. Cl. X.R.

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