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Патент USA US3025677

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March 20, 1962
J. M. s‘. KEEN
3,025,666
PROPELLING NOZZLES FOR JET PROPULSION GAS TURBINE ENGINES
' Filed May 6, 1960
z/OH/V M/CHAEZ S70E55’ WEE /v
By 9*
Attorney
'
I
nited States Patent O??ce
3,25,5b6
Patented Mar. 20, 1962
1
2
FIGURE 2 is an enlarged sectional view of a portion
of the engine of FIGURE 1.
3,025,666
PROPELLENG N OZZLES FOR JET PROPULSION
GAS TURBINE ENGINES
John Michael Storer Keen, Derby, England, assignor to
Rolls-Royce Limited, Derby, England, a company of
Great Britain
Filed May 6, 1960, Ser. No. 27,336
Claims priority, application Great Britain June 12, 1959
3 Claims. (Cl. 60-35.6)
pipe 14 whose downstream end is formed to provide a
According to the present invention there is provided a
pass passage 18 is supplied, by means not shown, with air
Referring to the drawings, 10 indicates a jet propulsion
gas turbine engine having a compressor 12, combustion
equipment and turbine equipment (not shown) and a jet
main, variable area, propelling nozzle 16.
The engine and jet pipe are enclosed within a nacelle
38 which extends from adjacent the compressor inlet to
10 adjacent the nozzle outlet and is radially spaced there
This invention relates to propelling nozzles for jet pro
from whereby there is de?ned an annular by-pass passage
pulsion gas-turbine engines.
18 which surrounds the engine and the jet pipe. The by
propelling nozzle for ‘a jet propulsion gasaturbine engine
compressed by the compressor 12.
comprising a main variable area nozzle adapted to be 15
A secondary variable area nozzle 20 is provided at the
mounted at, or to form part of, the downstream end of
downstream end of the passage 18_ The arrangement
the jet pipe of the said engine, an annular air duct sur
is such that the air ?owing through the passage 18 is
rounding said main nozzle or said jet pipe and provided
discharged through the nozzle 20 as an annular stream
with a secondary variable area nozzle such that air dis
closely surrounding the jet gases discharged through the
charged through the secondary nozzle forms an annular 20 nozzle 16. Reheat combustion equipment (not shown)
stream closely surrounding the jet gases discharged
through the main nozzle, and nozzle adjustment means
for varying the effective areas of the main and secondary
nozzles, said nozzle adjustment means being such as to
permit the effective area of the secondary nozzle to be 25
adjusted independently of that of the main nozzle when
is provided in the nozzle 16, the said equipment being
adapted to injet fuel into, and to effect combustion of
said fuel in, the exhaust gases passing through the nozzle
16, whereby to increase engine performance over a lim
ited period.
the latter area has a predetermined value.
Thus each of said nozzles may be provided with a
The outlet end of the nozzle 16 is defined by a series
of ?ap members 22 which are arranged in an annular
assembly. The ?ap members 22 are supported on pivot
series ‘of circumferentially arranged ?aps which may be
members 24 which are arranged transversely of the longi
moved so that ‘the effective areas of the nozzles may be 30 tudinal axis of the engine. The ?ap members 22 can thus
varied in accordance with different engine operating con
be swung towards and away from the longitudinal axis
ditions. The ?aps of the secondary nozzle preferably
' 0f the engine so as to vary the effective outlet area of the
extend downstream of those of the main nozzle.
nozzle 16.
Preferably the main and secondary nozzles are pro
Each ?ap member 22 is provided with a pair of upstand
vided with a common adjustment device operation of 35 ing, spaced ‘apart ?anges 26 on that face thereof which
which effects simultaneous adjustment of both said nozzles
is remote from the gas ?ow passage through the nozzle
at all times except when the effective area of the main
16, and carried between the ?anges 26 is a roller 28 which
nozzle is at the said predetermined Value.
is freely rotatable on a shaft, not shown, supported by
the ?anges 26.
Thus the adjustment device may comprise a cam mem
Each of the rollers 28 engages with one face of a re
ber engaging a movable part or parts of the main nozzle, 40
movement of said cam member effecting adjustment of
spective cam plate 30, each of the cam plates 30‘ being
said part or par-ts, whereby to adjust the effective area of
disposed in an inclined position and being carried on an
axially movable externally screw threaded spindle 32.
the main nozzle, at all times except when a predetermined
portion or portions of said cam member engages said
The latter form part of an actuating mechanism for turn
movable part or parts.
45 ing the i?ap members 22 about their pivots 24 either to
Preferably the cam member is movable axially of the
wards or away from the longitudinal axis of the engine.
main nozzle, the said portion or portions of the cam mem
In order to ensure that all of the cam plates 30 move
ber extending parallel to the ‘axis of the main nozzle.
at the same time and the same distance when they are
The invention also comprises a gas turbine jet propul
actuated they are all supported within two axially spaced
sion engine comprising a main variable area nozzle
apart frusto-conical rings 31 which are connected to
gether.
mounted at the downstream end of the jet pipe of the
engine, an annular passage surrounding the jet pipe and
Thus relative movements of the cam plates is pre
having at its downstream end a secondary variable area
vented.
nozzle, said annular passages being arranged for the ?ow
A strut 34 is provided on each cam plate 30 on that
therethrough of air (e.g. ram air or compressed air from 55 face thereof which is remote from the face engaged by
a compressor of the engine) which is discharged through
the roller 28. The strut 34 carries at its downstream
the secondary nozzle as an annular stream closely sur—
end a roller 35 which is movable in a track 36. The track
36 is mounted on ‘a further ?ap member 37 which is
rounding the jet gases discharged through the main nozzle,
and nozzle adjustment means for varying the effective
areas of the main and secondary nozzles, said nozzle
adjustment means being such as to permit the effective
area of the secondary nozzle to be adjusted independently
of that of the main nozzle When the latter area has a
predetermined value.
so
pivotally supported on the nacelle 38 enclosing the en—
gine. The ?ap members 37 are disposed in an annular
array, a flap member 37 being provided for each of the
?ap members 22.
Whilst the track 36 shown in the drawings is straight
it can if desired be curved so that when the ?aps 22 and
In order that the invention can be clearly understood 65 37 are actuated their relative positions are varied.
and readily carried into effect one construction of a pro
Each ?ap member 37 is spaced downstream of the re
pelling nozzle in accordance with the invention will now
spective ?ap member v22 whereby a duct 40 is de?ned
be particularly described, by way of example only, with
therebetween, the duct 40 communicating with the by
reference to the accompanying drawings, in which.
FIGURE 1 is a view showing a jet propulsion gas 70 pass passage 18.
The said actuating mechanism for causing axial move
turbine engine having a propelling nozzle in accordance
ments of each spindle 32 comprises a screw jack 42 hav~
with the present invention, and
3,025,666
4
3
ranged ?aps pivotally mounted on ‘the jet pipe for varying
ing an axially extending screw threaded bore in which
the spindle 32 is disposed.
the effective area of the same; a secondary variable area
nozzle mounted ‘at the downstream end of the annular
air duct, said secondary nozzle including a series of
It will thus be seen that when the screw jack 42 is ro
tated, the spindle 32, which is held against rotation by its
circumferentially arranged flaps pivotally connected to
connection to the cam plate 30, will be caused to move
axially. The cam plate 30' will therefore also move
axially whereby the associated ?ap 22 will (according to
the direction of movement of the cam plate 30) either be
the downstream end of said air duct for varying the ef
fective area of the same; means operatively connected
respectively to ‘and intermediate of the flaps of said main
moved inwardly towards the axis of the nozzle 16 or will
and secondary nozzles and movable axially with respect
be permitted to move away from this axis under the ac
tion of the gas pressure.
In order that all of the flap members 22 shall move in
unison and in the same direction, all of the screw jacks 42
are rotated by a common mechanism, the said mechanism
thereto through a predetermined range, said last-men
The gear teeth 45 engage with corresponding gear
teeth 46 formed on the exterior of each jack 4-2, and
thus when the annular member 44 is rotated the jacks
mined range; and an actuator member operatively con
nected to said ?rst means and said cam means for axially
tioned means including a ?rst means to vary the effective
area of said secondary nozzle through the entire pre
determined range and a cam means to vary the main
nozzle simultaneously with the variance of the secondary
comprising a fully annular member 44, only part of 15 nozzle through a portion of the predetermined range
while maintaining the effective area of the main nozzle
which is shown in the drawings, the member 44 being
constant during at least another portion of the predeter
provided with gear teeth 45 on its inner periphery.
moving the same to actuate the respective ?aps of said
main and secondary nozzles.
2. A propelling nozzle ‘for a gas turbine jet propulsion
engine comprising: a main nozzle, an annular air duct
surrounding said main nozzle, a secondary nozzle carried
by said air duct for discharging air through said second
ary nozzle in an annular stream closely surrounding jet
gases discharged through the main nozzle, said main
nozzle and said secondary nozzle each comprising a series
42 are all rotated in a common direction, at the same
speed whereby the movement of all the flaps 22 is equal.
The annular member 44 is supported in a ball race 46
as shown in FIGURE 2 of the drawings.
With the two sets of ?aps 2'2 and 37 in the position
shown in FIGURE 2 of the drawings, the outlet area of
the nozzle 16 is reduced to its permissible minimum to
obtain maximum thrust for take off and a convergent
nozzle is de?ned.
As can be seen from FIGURE 2 of the drawings, each
cam plate 30 is provided with a portion, indicated at 48,
which is parallel with the axis of the nozzle 16 whereby
of circumferentially arranged pivotally mounted ?aps
which are movable to vary effective areas of the respec
tive nozzles, a common adjustment device for varying
the effective areas of said main nozzle and said secondary
nozzle, said device comprising a member movable par
allel to the axis of the main nozzle, said member having
a plurality of camming surfaces and a plurality of arms,
the ?aps of said main nozzle having cam followers for
it is possible to adjust the position of the ?aps 37 with
out moving the iiaps 22.
Such an arrangement enables the area of the duct 40
de?ned by the ?aps 37 to be adjusted ?nely to reduce
thrust losses.
engaging said oamming surfaces and the flaps of said
secondary nozzle having guide tracks slidably engaging
When the nozzle above described is in use, air from the
said arms, said camming surfaces each having at least
by-pass passage 18 ?ows through the duct 49 between
the two sets of ?aps to surround the exhaust gasses
one portion extending parallel to the axis of the main
nozzle and enabling the effective area of said main nozzle
to remain constant while the effective area of said second
ary nozzle is varied during a predetermined portion of
the range of axial movement of said member.
and prevent premature expansion thereof, whereby thrust
losses are reduced or obviated.
It will be appreciated that instead of having a ?at por
tion at one end only of each cam plate 30 such a por
3. A propelling nozzle, as claimed in claim 1, includ
tion may be provided at both ends. Thus when the said 45
a plurality of circumferentially spaced screw jacks oper
reheat combustion equipment is in use and the flaps 22,
atively connected to said member, and a common opera‘ -
37 are moved to de?ne a convergent-divergent nozzle, ?ne
ing annular gear ring for engaging and operating said
adjustment may be made of the position of the flaps 37
without moving the ?aps 22.
screw jack simultaneously to impart movement to said
If desired a ?at portion may also be formed on each 50 member parallel to the axis of the main nozzle.
cam plate 30 at a point substantially midway of its length
whereby ?ne adjustment of the position of the flaps
37 may be made when the flaps 22 and 37 are positioned
for normal cruise conditions.
I claim:
References Cited in the ?le of this patent
UNITED STATES PATENTS
55
1. A gas turbine jet propulsion engine having a jet
pipe for discharging jet gases and ‘an annular air duct
surrounding the jet pipe for discharging an annular stream
of air closely'surrounding the discharge jet gases, the
improvement comprising: a main variable area nozzle 60
mounted at the downstream end of the jet pipe, said
main nozzle including a series of circumferentially ar
2,846,844
2,931,169
O’Rourke __________ __ Aug. 12, 1958
Glenn ______________ __ Apr. 5, 1960
2,932,163
Hyde ______________ __ Apr. 12, 1960
OTHER REFERENCES
Pearson: “Exhaust Nozzles for Supersonic Aircraft,”
Journal of the Royal Areonautical Society, vol. 62; No.
573; September 1958, pp. 658-662; page 662 relied on.
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