U.S. patent number 3,800,531 [Application Number 05/366,332] was granted by the patent office on 1974-04-02 for self-starting annular jet engine with plural burner and bypass duct.
Invention is credited to Thomas H. Sharpe.
United States Patent |
3,800,531 |
Sharpe |
April 2, 1974 |
SELF-STARTING ANNULAR JET ENGINE WITH PLURAL BURNER AND BYPASS
DUCT
Abstract
An engine including a self-starting engine compressor unit
comprising a burner duct defining a converging-diverging inlet at
its forward end, a converging exhaust nozzle at its rear end, and a
combustion chamber therebetween; a fuel injection device for
injecting fuel under pressure axially through the throat of the
inlet into the combustion chamber to draw air therewith into the
chamber; and preheater means for heating the chamber to a
predetermined temperature. The compressor unit may include a bypass
duct encircling the burner duct with an inlet opening forward of
the inlet to the burner duct and a converging exhaust opening
rearward of the exhaust nozzle so that air will be drawn through
the bypass duct by the jet pumping action of the exhaust gases from
the burner duct in combination with the exhaust opening in the
bypass duct. The fuel injection device may be equipped with
pressure responsive means for transferring the point of injection
from forward of the throat of the inlet of the burner duct to a
point rearward of the throat and within the combustion chamber. The
compressor unit may be embodied in a jet engine as a start stage
with intermediate and final ram-jet type stages.
Inventors: |
Sharpe; Thomas H. (Belvedere,
SC) |
Family
ID: |
26887228 |
Appl.
No.: |
05/366,332 |
Filed: |
June 4, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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191627 |
Oct 22, 1971 |
3750400 |
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Current U.S.
Class: |
60/263; 60/804;
60/39.52; 60/264; 60/39.49; 60/241; 60/269 |
Current CPC
Class: |
F02K
7/12 (20130101) |
Current International
Class: |
F02K
7/00 (20060101); F02K 7/12 (20060101); F02k
003/10 () |
Field of
Search: |
;60/263,203,267,264,269,39.52,39.49,39.36,241,242,247 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Croyle; Carlton R.
Assistant Examiner: Olsen; Warren
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my co-pending
application Ser. No. 191,627, filed Oct. 22, 1971, entitled
"Engine" now U.S. Pat. No. 3,750,400.
Claims
I claim:
1. A self-starting engine including:
a tubular housing defining a primary diverging inlet at its forward
end, an outwardly flaring bypass chamber intermediate its ends, and
a primary converging exhaust nozzle at its rear end;
a tubular outwardly flaring burner can mounted within said bypass
chamber concentrically therewith and defining an injection opening
at its forward end, a primary combustion chamber and a converging
exhaust opening at its rear end so as to form a bypass duct between
said can and said housing, said burner can including scoop means
projecting outwardly into said bypass duct to direct air passing
through said bypass duct into said primary combustion chamber of
said cam;
fuel nozzle means for spraying fuel into said primary combustion
chamber of said can; and,
a plurality of compressor units, each of said units comprising:
a burner duct including a compressor combustion chamber and a
compressor exhaust nozzle;
a converging-diverging compressor inlet at that end of said
compressor combustion chamber opposite said exhaust nozzle and
defining a reduced diameter compressor throat;
a fuel injection device for injecting fuel under pressure axially
through said throat of said compressor inlet and into said
compressor combustion chamber to draw air into said burner duct
through said compressor inlet; and,
preheater means for heating said compressor combustion chamber to a
predetermined temperature,
one of said compressor units arranged to discharge its exhaust
gases axially into said burner can through said injection opening
and the other of said plurality of compressor units mounted
circumferentially about said burner can within said bypass duct
forward of said primary exhaust nozzle of said housing.
2. The engine of claim 1 wherein each of said fuel injection
devices includes an injection nozzle having a discharge end, said
nozzle having a first position so that its discharge end is located
forwardly of said compressor throat and a second position so that
its discharge end is located within said compressor combustion
chamber rearwardly of said compressor throat.
3. The engine of claim 1 wherein burner can includes a side wall,
said side wall defining an opening therethrough immediately forward
of each of said scoop means for the passage of the air deflected by
said scoop means into said primary combustion chamber.
4. A self-starting engine including a compressor stage, an
iintermediate stage and a main thrust stage,
said compressor stage comprising:
a burner duct including an inner ring and an outer ring concentric
with said inner ring, said inner and outer rings defining an
annular compressor converging-diverging inlet having a reduced
diameter throat, an annular compressor combustion chamber
rearwardly of said inlet and an annular compressor exhaust nozzle
rearwardly of said combustion chamber;
a fuel injection device including a plurality of primary injection
nozzles circumferentially spaced about and forward of said
compressor throat, a plurality of secondary sets of injection
nozzles circumferentially spaced about the forward end of said
compressor combustion chamber rearwardly of said throat, one
secondary set of nozzles axially aligned with each of said primary
nozzles, and pressure responsive fuel valve means connecting said
primary and secondary sets of nozzles for controlling the flow of
fuel to said nozzles; and,
preheater means for heating said compressor combustion chamber to a
predetermined temperature including a plurality of heating coils,
one of said coils being axially with each of said primary
nozzles,
said intermediate stage comprising a first power unit and a second
power unit, said first power unit including:
a first inner tubular section and a first outer tubular section
concentrically arranged with respect to each other and with said
engine unit, said first inner and outer sections defining
there-between a first diverging inlet forward of said compressor
stage, inner and outer passages about said engine unit, a first
reduced diameter throat rearwardly of said exhaust nozzle of said
compressor stage, a first annular combustion chamber rearwardly of
said first throat, and a first converging exhaust nozzle at the
rear end thereof; and
first burner assembly mounted within said first combustion chamber
between said first inner and outer sections, said burner assembly
including a first annular diverging shroud liner and a plurality of
first fuel nozzles for injecting fuel within said liner;
and said second power unit including:
a second inner tubular section and a second outer tubular section
concentrically arranged with respect to each other and with said
first power unit, said second inner and outer tubular sections
defining therebetween a second converging-diverging inlet at their
forward ends axially aligned with said first exhaust nozzle of said
first power unit for receiving the exhaust gases therefrom, a
second annular combustion chamber, and second converging exhaust
nozzle at their rear ends; and,
a second burner assembly mounted within said second combustion
chamber between said second inner and outer sections, said second
burner assembly including a second annular diverging shroud liner
and a plurality of second fuel nozzles for injecting fuel within
said second liner;
said main thrust stage receiving the exhaust gases from said
intermediate stage and including:
a main inner tubular section and a main outer tubular section
concentrically arranged with respect to each other and to said
second inner and outer tubular sections of said second power unit,
said main inner and outer sections defining therebetween a main
coverging-diverging inlet at their forward ends axially aligned
with said second exhaust nozzle of said second power unit for
receiving the exhaust gases therefrom, a main annular combustion
chamber, and a main converging exhaust nozzle at their rear ends;
and,
a main burner assembly mounted within said main combustion chamber
between said main inner and outer tubular sections including a main
compound annular shroud liner and a plurality of main fuel nozzles
for injecting fuel within said main shroud liner; and,
said engine further including: thrust
a main cowling tube mounting said compressor stage, said
intermediate stage and said main thrust stage concentrically
therein and defining a base inlet forward of said compressor stage;
an annular bypass duct around the outside of said compressor stage,
said intermediate stage and said main thrust stage; and a base
converging exhaust opening rearwardly of said main thrus stage,
said first power unit and said second power unit defining a first
inner space between said first exhaust nozzle of said first power
unit and said second inlet of said second power unit communicating
with the opening in said first inner tubular section and a first
outer space communicating with said bypass duct to draw air into
said second power unit; and said second power unit and said main
thrust stage defining a second inner space between said second
exhaust nozzle of said second power unit and said main inlet of
said main thrust stage communicating with the opening in said
second inner tubular section and a second outer space communicating
with said bypass duct to draw air into said main thrust stage.
5. The engine of claim 4 wherein said fuel injection device further
includes a fuel line connected to said fuel valve means, said fuel
valve means selectively transferring the fuel flowing through said
fuel line from said primary to said secondary nozzles.
6. The engine of claim 5 wherein said first and second shroud
liners and said main compound shroud liner each define a
converging-diverging liner inlet with a liner throat and wherein
said first, second and main fuel nozzles are constructed and
arranged to respectively discharge fuel forwardly of and axially
through said liner throats.
7. A self-starting engine comprising:
a compressor stage including:
a compressor burner duct comprising a compressor combustion chamber
and a compressor exhaust tube,
a converging-diverging compressor inlet at that end of said
compressor combustion chamber opposite said exhaust nozzle and
defining a reduced diameter compressor throat,
a fuel injection device for injecting fuel under pressure axially
through said throat of said compressor inlet and into said
compressor combustion chamber to draw air into said burner duct
through said compressor inlet comprising an injection nozzle having
a discharge end, said nozzle having a first position so that its
discharge end is located forwardly of said compressor throat and a
second position so that its discharge end is located within said
compressor combustion chamber rearwardly of said compressor throat,
and,
preheater means for heating said compressor combustion chamber to a
predetermined temperature;
an intermediate stage including:
an intermediate annular burner duct concentrically located about
said compressor burner duct defining an annular
converging-diverging intermediate inlet, an intermediate annular
combustion chamber and an intermediate exhaust tube, and,
intermediate fuel injection means for injecting fuel within said
intermediate combustion chamber; and,
a main thrust stage including:
a main annular burner duct concentrically located about said
intermediate burner duct defining an annular converging-diverging
main inlet, a main annular combustion chamber and a main exhaust
tube, and,
main fuel injection means for injecting fuel within said main
combustion chamber;
said compressor exhaust duct terminating within said intermediate
exhaust duct and said intermediate exhaust duct terminating within
said main exhaust duct so that the exhaust gases from said
compressor exhaust duct will cause air to be drawn into said
intermediate combustion chamber through said main inlet by jet
pumping action.
8. The engine of claim 7 further including regenerative compressor
means for injecting a prescribed amount of the exhaust gases in
said engine reareardly through said intermediate and said main
inlets.
9. The engine of claim 8 wherein said regenerative compressor means
includes a first unit for injecting a prescribed amount of the
exhaust gases in said intermediate combustion chamber rearwardly
through said intermediate inlet and a second unit for injecting a
prescribed amount of the exhaust gases in said main combustion
chamber rearwardly through said main inlet.
10. The engine of claim 9 wherein said first unit comprises:
a first plurality of injectors positioned within said intermediate
inlet forward of the throat of said inlet, said first injectoss
circumferentially spaced about said inlet in a first transverse
plane, each of said first injectors injecting exhaust gases
rearwardly therefrom and laterally thereof,
a second plurality of injectoss positioned wtthin said intermediate
inlet forward of said first injectors, said second injectors
circumferentially spaced about said inlet in a second transverse
plane and staggered with respect to said first injectors, each of
said second injectors injecting exhaust gases rearwardly therefrom
and laterally thereof and,
a first return duct connected to said first and second injectors at
one end and said intermediate combustion chamber at the other end
for supplying exhaust gases from said intermediate combustion
chamber to said injectors; and,
wherein said second unit comprises:
a third plurality of injectors positioned within said main inlet
forward of the throat of said inlet, said third injectors
circumferentially spaced about said inlet in a third transverse
plane, each of said third injectors injecting exhaust gases
rearwardly therefrom and laterally thereof,
a fourth plurality of injectors positioned within said main inlet
forward of said third injectors, said fourth injector
circumferentially spaced about said inlet in a fourth transverse
plane and staggered with respect to said third injectors, each of
said fourth injectors injecting exhaust gases rearwardly therefrom
and laterally thereof and,
a second return duct connected to said third and fourth injectors
at one end and said main combustion chamber at the other end for
supplying exhaust gases from said main combustion chamber to said
injectors.
Description
BACKGROUND OF THE INVENTION
Because jet engines must be capable of operating at low plane
speeds. currently used engines require a compressor stage for
supplying air under pressure to the burner section thereof and a
turbine stage driven by the exhaust gases of the burner section to
rotate the compressor stage. This requirement for rotating
machinery has increased the weigh of the engine as well as limited
the maximum temperatures within the engine. Also, the high
rotational speed of the rotating parts has required critical
dynamic balancing of the parts and extensive maintenance to keep
the engine operating properly.
SUMMARY OF THE INVENTION
These and other problems associated with the prior art are overcome
by the invention disclosed herein by providing a means for
supplying air to the burner section of the engine which requires no
rotating parts in the compressor itself or in the engine after the
burner section. The invention maintains operation while the engine
is stationery or moving at slow speeds. Because of the lack of
moving parts, the temperatures within the engine can be raised to
produce a more effective operation.
The apparatus of the invention includes a compressor start stage
comprising a burner duct including a burner section and an exhaust
nozzle, an inlet duct at that end of the burner duct opposite the
exhaust nozzle, a fuel injection device for injecting fuel under
pressure axially through the reduced diameter throat of the inlet
duct and into the burner duct to draw air into the burner section
through the inlet duct, and a pre-heater for heating the burner
section. The exhaust from the start stage may be injected through
the inlet duct of at least one intermediate stage to achieve a jet
pump action therethrough and pressurize the burner section of the
intermediate stage. Fuel injected into the intermediate stage
supports combustion therein and the exhaust therefrom may be
injected into the main engine stage to produce combustion and a
final thrust.
These and other features and advantages of the invention will
become more fully understood upon consideration of the following
specification and accompanying drawings wherein like characters of
reference designate corresponding parts throughout the several
views and in which:
FIG. 1 is an enlarged longitudinal cross-sectional view of one
embodiment of the invention;
FIG. 2 is a front view of the start stage of FIG. 7;
FIG. 3 is an enlarged cross-sectional view of the fuel injection
head of the start stage of FIG. 1;
FIG. 4 is a longitudinal cross-sectional view showing the
embodiment of FIG. 1 installed in an engine;
FIG. 5 is a transverse cross-sectional view taken along line 5--5
in FIG. 4;
FIG. 6A is a longitudinal cross-sectional view of a portion of
another embodiment of the invention;
FIG. 6B is a continuation of FIG. 6A showing the rest of the
embodiment;
FIG. 7 is a cross-sectional view taken along line 7--7 in FIG.
6A;
FIG. 8A is a longitudinal cross-sectional view of a portion of a
second embodiment of the invention;
FIG. 8B is a continuation of FIG. 8A;
FIG. 9 is an inlet end view of the embodiment of FIG. 8A;
FIG. 10 is an enlarged cross-sectional view of one unit of the
start stage of FIG. 8A;
FIG. 11 is an inlet end view of FIG. 10;
FIG. 12 is a longitudinal cross-sectional view of still another
embodiment of the invention;
FIG. 13 is a front view of the embodiment of FIG. 12;
FIG. 14 is a cross-sectional view taken along line 14--14 in FIG.
13; and,
FIG. 15 is an enlarged portion of FIG. 12.
These figures and the following detailed description disclose
specific embodiments thereof, however, it is to be understood that
the inventive concept is not limited thereto since it may be
incorporated in other forms .
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
Referring now to FIGS. 1-3, the first embodiment of the invention
includes a self-starting jet pump compressor unit 10. This unit is
capable of sustaining combustion at zero forward speed and to
produce an increased pressure at its exhaust or pump end.
The unit 10 includes a generally cylindrical burner duct 11 with an
annular duct wall 12 forming a substantially constant diameter
burner chamber 14 intermediate its ends, a converging-diverging
inlet 15 with a reduced diameter throat 16 smaller than the
diameter of the burner camber 14 at the front end of duct 16, and a
converging exhaust nozzle 18 at the rear end of duct 11 with a
throat 19 of a diameter smaller than that of chamber 14.
A fuel injection assembly 20 is positioned just forwardly of inlet
15 for injecting fuel through inlet 15 and into chamber 14 axially
along the centerline CL of duct 11. Referring to FIG. 3, the
assembly 20 includes a cylindrical stationary housing 21
concentrically mounted forwardly of inlet 15 by struts 22 attached
to duct wall 12. Housing 21 defines an axially extending
cylindrical passage 24 concentric about centerline CL of duct 11.
An inwardly extending annular retaining lip 25 extends around and
projects into passage 24 at its rear end and a similar annular
retaining lip 26 extends around and projects into passage 24 at its
forward end. An annular abutment 28 extends around passage 24 at
its central portion.
An intermediate extension tube 30 is slidably received in passage
24 between lip 25 and abutment 28. Tube 30 includes a cylindrical
body 31 of a constant diameter just sufficient to slidably pass
through the opening of lip 25 and an annular projecting flange 32
at the forward end thereof just sufficient to slidably move along
passage 24 but be retained between abutment 28 and lip 25. A
compression coil spring 34 is received about the body 31 of tube 30
between flange 32 and lip 25 to constantly urge tube 30 toward
abutment 28. A central support passageway 35 axially extends
through tube 30 with an annular inwardly extending lip 36 at its
rear end and a similar lip 38 at its forward end.
A fuel nozzle tube 40 is slidably received in passageway 35, and
includes a main body portion 41 of constant diameter just
sufficient to pass through the opening of lip 36 with an annular
outwardly projecting flange 42 at its forward end sufficient to
slidably move in passageway 35 and be retained between lips 36 and
38. A compression coil spring 44 is received about the main body
portion 41 between lip 36 and flange 42 to constantly urge tube 40
forwardly against lip 38 in passageway 35. An axially extending
fuel passage 45 is defined through nozzle tube 40 which
communicates with passage 24 in housing 21 at its forward end and
into the burner duct 11 at its rear end.
An inlet spike 50 is slidably mounted about housing 21 and in
passage 24 forwardly of abutment 28 and includes a central shaft 51
of a constant diameter just sufficient to slidably pass through the
opening defined by lip 26, a disc 52 on the rear end of shaft 51
slidably received in the forward portion of passage 24 and retained
between abutment 28 and lip 26, and a conical spike head 54 on the
forward end of shaft 51 and extending back over the housing 21. A
compression coil spring 55 is received around shaft 51 between disc
52 and lip 26 to constantly urge spike 50 rearwardly toward
abutment 28.
A fuel line 56 communicates with passage 24 through abutment 28 and
with a pressurized fuel supply source (not shown). In the fully
retracted position, the rear end of the intermediate extension tube
30 is substantially flush with the rear end of housing 21 and the
discharge end of the nozzle tube 40 is positioned axially within
the inlet 15 forward of its throat 19 so that fuel discharged from
fuel passage 45 will be injected axially through throat 19 into the
burner chamber 14. The spike head 54 is fully retracted rearwardly
over housing 21 and about struts 22. The operation of the assembly
20 will be explained in more detail hereinafter.
A preheater assembly 60 is mounted in the burner chamber 14 for
preheating same prior to injection of fuel therein in order to
start unit 10. Assembly 60 may be any of a number of available
preheating means and is shown as a heating coil 61 carried within
appropriate recesses 62 around the inside of duct wall 12 at the
burner chamber. This allows substantially unrestricted passage of
the combustion medium through chamber 14. Coil 16 is connected to
an appropriate power source (not shown) to heat same as will be
explained.
Fuel line 56 is connected to the pressurized fuel supply source
through a heat transfer section 64 located in duct wall 12 at the
exhaust nozzle 18 and includes a series of passages 65 in duct wall
12. The fuel passes through the passages 65 on its way to the fuel
injection assembly 20 to be heated while at the same time cooling
the duct wall 12.
A by-pass duct 70 is concentrically located about the burner duct
11 and defines a central opening 71 therethrough into which the
duct 11 is positioned on struts 72. The duct wall 74 defines a
diverging inlet 75 just forward of the inlet 15 of duct 11 and a
converging-diverging outlet 76 just rearwardly of exhaust nozzle
18. As combustion takes place within burner chamber 14, the
discharging exhaust gases from the exhaust nozzle 18 pass through
the reduced diameter throat 78 of outlet 76 to cause air to be
drawn into inlet 75 by a jet pump effect.
In order to retain the combustion within the burner chamber 14,
conventional flame holders 79 are concentrically mounted in burner
chamber 41 rearwardly of the throat 16 of inlet 15. The flame
holders 79 are carried by mounting bars 80 attached to duct wall 12
of the duct 11. Igniter plugs 81 may be provided to start
combustion.
A feedback bleed tube 90 may be fitted to the duct 11 and provided
with an inlet 91 at the converging section of exhaust nozzle 18. A
forwardly facing scoop 92 is provided within duct wall 12 to direct
a small portion of the high velocity exhaust gases into a pressure
reservoir 94 in tube 90. The trapped gases pressurized the tube 90
and travel forwardly along tube 90 to a manifold 95 in struts 22 to
pressurize same. The gases then pass from manifold 95 back into
inlet 15 through nozzles 96 to force more air into chamber 14.
OPERATION
In operation, power is first supplied to the preheater assembly 60
to heat the air within the burner chamber 14 to the approximate
ignition temperature of the fuel. This also heats the fuel within
the heat transfer section 64 so that it will be substantially
completely vaporized when it leaves the passage 45 in fuel nozzle
tube 40. When the appropriate temperature is reached, the fuel
supply injects the fuel through the passage 24 and out of the fuel
passage 45 through the throat 16 of inlet 15 and into the heated
air in the burner chamber 14. The igniter plugs 81 are powered in
conventional manner so that as the incoming high velocity fuel
stream mixes with the air combustion takes place. At the same time,
the incoming fuel stream draws more air into burner chamber 14 to
pressurize same and supply more air to support combustion. The
preheater assembly 60 and igniter plugs 81 are then de-powered and
the combustion is self-sustaining. It is to be understood that the
preheater assembly 60 may be integrated with the heat transfer
section 64 or that the fuel may be preheated before it reaches the
section 64 and this heat used to heat chamber 14 without or in
combination with the assembly 60.
As the exhaust gases exit through the exhaust nozzle 18 of duct 11,
they pass through the throat 78 of outlet 76 to create a suction at
the inlet 75 to draw additional air into unit 10 to further
pressurize the burner chamber 14.
Since the unit 10 is designed for use as a compressor stage in a
jet engine as will be described, the fuel injection assembly 20 is
provided with means for moving the point of injection of the fuel
from forward of throat 16 to a position behind the throat in burner
chamber 14 when the pressure within the burner chamber 14 due to
the ram effect from the velocity of the unit is sufficient to
support combustion. This is provided by increasing the pressure of
the fuel being supplied in response to ram pressure to a point
where the intermediate extension tube 30 and fuel nozzle tube 40
are fully extended against the force of springs 34 and 44 as seen
by dashed lines in FIG. 1. This converts unit 10 into a ram jet. At
the same time, the spike 50 is moved forwardly as shown by dashed
lines in FIG. 1 to open up the inlet 15 and allow more air to enter
the unit 10. When the incoming air to inlet 15 becomes supersonic,
spike head 54 of inlet spike 50 also generates a shock wave ahead
of the inlet 15 to increase the static pressure.
The fuel nozzle tube 50 may also be equipped with multiple nozzles,
each directing a stream of vaporized fuel substantially axially
through the throat 16 of inlet 15 in lieu of the single fuel
passage 45. This allows more fuel to be injected into the burner
chamber 14 while at the same time generating enough jet pumping
effect to force the necessary additional air into chamber 14 to
support combustion and provide the necessary mixing of fuel and
air.
ENGINE INSTALLATION
As seen in FIGS. 4 and 5, units 10 are installed in an engine 100
to provide sufficient pressure within the engine to operate same
even when the engine is stationary. Engine 100 has a main duct tube
101 having an annular side wall 102. Wall 102 defines a diverging
inlet opening 104 with a main burner chamber 105 of increasing
diameter thereafter and terminating in a converging outlet 106. A
tapered burner can 108 is concentrically located within chamber 105
by struts 109 between the side wall 102 of tube 101 and the can
wall 110 of burner can 108. The rear end of can wall 110 forms a
converging exhaust nozzle 111 which discharges through the larger
diameter outlet 106. Burner can 108 is provided with
dircumferentially extending slots 112 with forwardly facing air
scoops 114 along the rear endges of slots 112 as will be
explained.
The smaller forwardly facing end of burner can 108 joins with the
rear end of a compressor unit 10 so that the exhaust gases and air
discharged through the outlet 76 of unit 10 moves axially
rearwardly along the centerline CL-A of the engine 100 and burner
can 108. An annular fuel manifold 115 is positioned in burner can
108 behind the outlet 76 of unit 10 and is provided with rearwardly
facing nozzles 116 of conventional design for spraying the fuel
into can 108. Flame holders 117 may be provided in cna 108 to
retain the flame.
A plurality of units 10 are positioned in the annular passage 120
between the burner can 108 and side wall 102 of duct tube 101 near
the rear end of the can 108. The units 10 are equally spaced
circumferentially about can 108 so that the exhaust gases and air
discharged from each of their outlets 76 are directed through the
converging outlet 106 of duct tube 101 to draw air moving along the
annular passage 120 into the burner can 108.
In operation, the units 10 are ignited as set forth hereinabove to
draw air into the inlet opening 104. The unit 10 in front of the
burner can 108 discharge the air-exhaust gas mixture therefrom
axially along the burner can 108 while the remaining units 10
discharge the air-exhaust gas mixture through the outlet 106 to
draw air along the annular passage 120. The forwardly facing air
scoops 114 direct a portion of the air from passage 120 into the
interior of can 108 and the jet pumping action of the discharging
air-exhaust gas mixture also draws additional air into the burner
can 108.
After the units 10 are operating, fuel is supplied to manifold 115
and discharge rearwardly by nozzles 116 where it is mixed with the
air and exhaust gas mixture within burner can 108 and ignited by
the heat of the exhaust gases from the forward unit 10 and
combustion is sustained for the engine 100 to produce thrust.
SECOND ENGINE INSTALLATION
Referring to FIGS. 6A-7, the unit 10 is incorporated in an engine
200 of the axial flow type. The unit 10 has the by-pass duct 70
removed therefrom and is equipped with a variable throat exhaust
nozzle assembly 201. Assembly 201 includes a plurality of arcuate
vanes 202 slidably positioned about the nozzle 18 of duct 11 and
selectively positioned by a plurality of fluid cylinders 204. An
appropriate guide 205 is provided to cause the vanes 202 to pass
along the duct wall 12 to selectively throttle the exhaust gases
being discharged from the burner chamber 14 as will be
explained.
The unit 10 is concentrically mounted in the forward end of a
cowling tube 206 described below by a pair of mounting struts 208.
Mounted rearwardly of the unit 10 concentrically in tube 206 is an
intermediate stage 210 carried by struts 208.
The intermediate stage 210 is aligned with the discharging exhaust
gases from unit 10 and receives additional air from the jet pump
arrangement at the forward end thereof to support combustion
therein. Stage 210 includes a main tube 211 with an annular tube
wall 212 concentrically located about the centerline CL-B of engine
200. Tube 211 defines a converging-diverging inlet 214 at its
forward end spaced rearwardly of the vanes 202 on unit 10. The
diameter of the throat 215 of inlet 214 is larger than the maximum
opening provided by vanes 202.
Rearwardly of inlet 214 wall 212 defines a combustion chamber 216
and the rear end of tube 210 defines a converging exhaust opening
218. A fuel manifold 219 is positioned around the outside of tube
wall 212 at the forward end of combustion chamber 216 with a
plurality of fuel nozzles 220 of conventional design protruding
through the tube wall 212 into the combustion chamber 216. An inlet
spike 221 may be mounted in the forward end of combustion chamber
216 to act as a diffuser section within chamber 216 especially at
supersonic air-exhaust gas mixture flow rates through the throat
215 of inlet 214. Flame holders 222 may be provided aft of the fuel
nozzles 220 to maintain the flame within combustion chamber
216.
A throttling assembly 230 complimentary to the assembly 201 of unit
10 is provided forward of inlet 214. Assembly 230 includes a
plurality of movable vanes 231 around inlet 214 to define a
converging-diverging opening. Vanes 231 are carried by the forward
end of tube wall 212 and selectively positioned by a plurality of
fluid cylinders 234 so as to vary the annular opening between vanes
202 and the converging walls 235 of vanes 231. This serves to vary
the amount of air pumped through the inlet 214 of stage 210 by the
jet pumping action of the exhaust from unit 10.
A variable throat exhaust nozzle assembly 240 is provided about the
exhaust opening 218 of tube 211. The nozzle assembly 240 is similar
in construction to the nozzle assembly 201 with a plurality of
arcuate vanes 241 slidably mounted in guide 242 and positioned by
cylinders 244 so as to vary the discharge opening of stage 210 and
throttle the exhaust therefrom.
A generally semi-circular cowling 250 is provided about the
throttling assembly 230 with its open mouth 251 extending over the
rear end of unit 10 to provide an air metering passage 252 into the
inlet 214 of stage 210.
A main thrust stage 260 is mounted within cowling tube 206
rearwardly of intermediate stage 210 by struts 261 and aligned with
the discharging exhaust gases from unit 10. Additional air is
supplied thereto by the jet pump arrangement at the forward end
thereof to support combustion therein.
The main thrust stage 260 is similar in construction to the
intermediate stage 210 except larger with a main thrust tube 262
having a converging-diverging inlet 264, combustion chamber 265,
and a converging-diverging exhaust outlet 266. A fuel manifold 268
encircles the outside of tube 262 and has a plurality of
conventional fuel nozzles 269 projecting into combustion chamber
265. A plurality of flame holder rings 270 are positioned in
chamber 265 and an inlet spike 271 is mounted on struts 272 in the
forward end of combustion chamber 265 to act as a diffuser section
in chamber 265, especially at supersonic air-exhaust gas mixture
flow rates through inlet 264.
A throttling assembly 274 similar to assembly 230 and complimentary
to the exhaust nozzle assembly 240 at the rear end of intermediate
stage 210 is provided on the forward end of tube 262. The assembly
274 cooperates with assembly 240 similarly to the co-operation
between assembly 230 and assembly 201 to selectively throttle the
amount of air drawn through the inlet 264 of the main thrust stage
260 by the jet pumping action of the exhaust gases discharged by
intermediate stage 210. Assembly 274 includes a plurality of
movable vanes 275 around inlet 264 to form a converging-diverging
opening and slidably mounted on guide 276. A plurality of fluid
cylinders 278 control the position of the vanes 275.
A generally semi-circular cowling 280 is provided about the
throttling assembly 274 similarly to cowling 250 of intermediate
stage 210. The forwardly facing open mouth 281 of cowling 280
extends over the rear end of stage 210 to provide an air metering
passage 282 into the inlet 264 of the main thrust stage 260. The
cowling 280 includes an cylindrical annular outer wall 284 which
extends rearwardly from mouth 281 to join with the thrust tube 262
at its combustion chamber. This provides an annular by-pass duct
285 around the main thrust stage 260 as will be explained.
A cooling ring assembly 286 is positioned around the reduced
diameter portion of tube 262 at the exhaust outlet 266 to direct a
portion of the air from the by-pass duct 285 along the outer
surface of tube 262 and cool same.
The cowling tube 206 defines the outside of the engine and mounts
the compressor unit 10, intermediate stage 210 and main thrust
stage 260 in its central cavity 290. Tube 206 has an annular
cylindrical side wall 291 which projects forwardly of the unit 10
to provide a diverging inlet duct 292 forwardly of unit 10 and
terminates substantially in the same plane as the exhause outlet
266 of the main thrust stage 260.
A flap-type augmentated exhaust nozzle assembly 294 is mounted on
the rear end of cowling tube 206. Assembly 294 includes a plurality
of flaps 295 hinged to the tube 206 and positioned by fluid
cylinders 296 in known manner. The varying of the position of flaps
295 serves to control the amount of by-pass air drawn through duct
285 by the jet pumping action of the exhaust from the main thrust
stage 260.
OPERATION OF SECOND ENGINE INSTALLATION
In operation, the compressor unit 10 is ignited as set forth
hereinabove. Its exhaust gases are injected axially through the
inlet 214 of intermediate stage 210 which creates a jet pumping
action to draw additional air into stage 210 through the annular
metering opening defined between vanes 202 and 231 and also to draw
additional air into the inlet 15 of unit 10. The jet pumping action
of unit 10 pressurizes the burner chamber 216 of stage 210.
When fuel is sprayed into the chamber 216 by nozzles 220, ignition
takes place because of the heat from the exhaust gases of unit 10
and operation of the intermediate stage 210 starts. The discharging
exhaust gases from stage 210 are injected through the inlet 264 of
the main thrust stage 260. This causes air to be drawn into the
stage 260 through the annular opening between vanes 241 and 275 to
pressurize the burner chamber 265 thereof. When fuel is supplied
via nozzle 269 to chamber 65, ignition takes place from the heat of
the exhaust gases of stage 210. The exhaust gases from stage 260
discharging through the nozzle assembly 294 causes additional air
to be drawn into the engine via the inlet duct 292 to further
pressurize the engine.
Because control systems for controlling the amount of fuel injected
into the engine 200 as well as the position of the assemblies 201,
230, 240, 274 and 294 are available, these controls are not
described. It will be seen that the jet pumping action of each
stage is summed, sufficient operating pressure is maintained within
the engine.
THIRD ENGINE INSTALLATION
Referring now to FIGS. 8A-10, the invention is embodied in engine
300 having a compressor stage 301, an intermediate stage 302, and a
main thrust stage 304.
Engine 300 includes a main cowling tube 305 which mounts the
various engine stages therein. The compressor stage 301 includes a
plurality of compressor units 310 positioned within the forward
portion of tube 305 and equally spaced concentrically about the
centerline CL-3 of engine 300. The compressor units 310 are mounted
between an inner tube ring 311 and an outer tube ring 312
concentrically located with respect to each other and to the
centerline CL-3 to form a compressor annulus 314 therebetween. An
outwardly projecting bend 315 is formed in inner ring 311 just
inwardly of its forward end and, in conjunction with a
complementary inwardly projecting bend 316 formed in outer ring
312, forms an annular throat 318 between the rings 311 and 312. The
rear end of inner ring 311 is angled outwardly to form a nozzle
flange 316 and in conjuction with the inwardly angled complementary
flange 320 of outer ring 312, forms an annular exhaust nozzle 321
between rings 311 and 312. The rings 311 and 312 are arranged so
that the throat 318 is axially aligned with exhaust nozzle 321.
Each unit 310 as best seen in FIGS. 10 and 11 includes a primary
fuel metering assembly 325 positioned in the converging portion of
annulus 314 forwardly of the throat 318 thereof. Assembly 325 has a
cylindrical body 326 with a forwardly facing projection 328
extending toward the inlet of annulus 314 and a rearwardly facing
low pressure fuel nozzle 329 for injecting fuel axially through the
throat 318 as will be explained. Unit 310 is mounted by struts 330
connected to rings 311 and 312. Positioned rearwardly of throat 318
in alignment with assembly 325 is a ring manifold 331 having a
plurality of rearwardly facing fuel nozzles 332 in the forward end
of the annular combustion chamber 334 defined by rings 311 and
312.
Each nozzle 329 and ring manifold 331 is supplied fuel from a
distribution manifold 335 extending around the outside of the ring
312 within bend 316. Each nozzle 329 is connected to manifold 335
through a low pressure bypass valve 336 that restricts fuel flow to
the nozzle inversely to the inlet pressure at annulus 314 to allow
the fuel to flow to nozzle 329 at lower inlet pressure and decrease
the flow as inlet pressure increases until the fuel flow is cut off
at nozzle 329 when a predetermined inlet pressure is reached. Each
ring manifold 331 is connected to manifold 335 through a high
pressure bypass valve 338 which allows fuel to flow to ring
manifold 331 when the inlet pressure at annulus 314 reaches the
predetermined valve at which the fuel flow is cut off to nozzle
329. The fuel is supplied to the manifold 335 from the fuel source
through a heat transfer tube 337 in the combustion chamber 334 to
preheat the fuel prior to injection through nozzle 329 and nozzles
332. Flame holders 340 may be positioned in the combustion chamber
334 behind each fuel metering assembly 325 and ring manifold 331 to
retain the flame in combustion chamber 334.
A heating coil 345 is placed in the combustion chamber 334
rearwardly of flame holders 340 behind each fuel metering assembly
325 so that preheating as described for unit 10 can take place.
This insures starting of each unit 310.
An air bleed tube 346 similar to tube 90 for unit 10 connects the
rear end of combustion chamber 334 with a chamber 348 in struts
330. Each tube 346 has a forwardly facing scoop 349 projecting into
chamber 334 to direct the gases into a reservoir 350 in tube 346. A
plurality of rearwardly facing ports 351 in struts 330 inject the
gases from chamber 348 through throat 318 to assist in pressurizing
combustion chamber 334.
An inner tubular section 355 is positioned inside of ring 311 and
concentrically therewith by struts 356 to define an inner bypass
359 between section 355 and ring 311. An outer tubular section 358
is positioned outside of ring 312 and concentrically therewith to
define an outer bypass 360 between section 358 and ring 312. An
outwardly angled flange 361 is provided at the forward end of
section 355 and, in conjunction with an inwardly angled flange 362
on the forward end of section 358, defines a diverging inlet 364
forward of the inlet of the compressor stage 301. The rearmost end
of tubular section 355 is provided with an outwardly angled flange
365, which, in conjunction with an inwardly angled flange 366,
forms an annular exhaust nozzle 368 for the first power unit 370 of
intermediate stage 302.
Just rearwardly of the exhaust nozzle 321 of compressor stage 301,
the inner tubular section 355 is provided with an outwardly
projecting bend 371, which, in conjunction with a complementary
inwardly projecting bend 372 in the outer tubular section 358,
forms the inlet 374 of power unit 370 with throat 375 having a
slightly larger opening than that of the exhaust nozzle 321 of
compressor stage 301 and axially aligned therewith. This forms an
annular combustion chamber 376 between inlet 374 and exhaust nozzle
368. A ring 378 covers the depression of bend 371 and a ring 379
covers the depression of bend 372 to provide a smooth inner surface
along section 355 and a smooth outer surface along section 358.
An annular cone shaped burner shroud liner 380 is positioned in
combustion chamber 376. The forwardly facing converging portions of
the side walls 377 of liner 380 are shaped to define an annular
converging-diverging inlet 383 as best seen in FIG. 8A with an
annular throat 387. A plurality of fuel nozzles 381 are provided
which are connected to the fuel source through heat transfer coil
373 in combustion chamber 376 just forwardly of exhaust nozzle 368.
The nozzles 381 are circumferentially spaced about the inlet 383 so
that the fuel discharged rearwardly therefrom forwardly of the
throat 387 will pass axially through the throat 387 to pump air
therewith into the linear 380. The liner 380 serves as a flame
holder to retain the combustion flame within chamber 376.
The second power unit 385 of intermediate stage 302 includes an
inner tubular section 386 and an outer tubular section 388. The
forward ends of sections 386 and 388 project just forwardly of
exhaust nozzle 368 of the first power unit and are provided with
outwardly and inwardly directed projections 389 and 390
respectively to form an annular converging-diverging inlet 391 with
throat 392 axially aligned with an exhaust opening in nozzle 368.
Inlet passages 394 and 395 are defined between projection 389 and
flange 365 and between projection 390 and flange 366. The rearmost
ends of tubular sections 386 and 388 are provided respectively with
an outwardly flaring flange 396 and an inwardly flaring flange 398
to form a converging exhaust nozzle 399.
An annular combustion chamber 400 is defined between inlet 391 and
exhaust nozzle 399. An annular cone shaped burner shroud liner 401
is positioned in combustion chamber 400 as best seen in FIG. 8A.
The forwardly facing converging portions of the side walls 403 of
liner 401 are shaped to define an annular converging-diverging
inlet 407 with an annular throat 413. A plurality of fuel nozzles
402 are circumferentially spaced about the inlet 407 so that fuel
discharged rearwardly therefrom forwardly of the throat 413 will
pass axially through the throat 413 to pump air therewith into the
liner 380. The nozzles 402 are connected to the fuel source through
a heat transfer coil 417 positioned in combustion chamber 400 just
forwardly of exhaust nozzle 399.
The main thrust stage 304 is positioned rearwardly of the second
power unit 385 of intermediate stage 302 and includes an inner
tubular section 404 projecting within the flange 396 of unit 385
and on outer tubular section 405 projecting around flange 398 of
unit 385. The forward end of section 404 has an inwardly extending
projection 406 to form an annular converging-diverging inlet 408
with an inwardly extending projection 409 on the forward end of
tubular section 405. An annular inner inlet duct 410 to stage 304
is defined between flange 396 of unit 385 and projection 406 and an
annular outer inlet duct 411 is defined between flange 398 of unit
385 and projection 409.
The rearmost end of tubular section 404 has an outwardly flaring
flange 412 which forms a diverging exhaust nozzle 414 with an
inwardly flaring flange 415 at the rearmost end of tubular section
405. This defines an annular combustion chamber 416 between inlet
408 and exhaust nozzle 414.
A compound burner can assembly 418 is positioned in combustion
chamber 416. Can assembly 418 includes an annular cone shaped inner
shroud liner 419 and outer shroud liner 420. The forwardly facing
converging portions of the side walls 423 of inner liner 419 are
shaped to define an annular converging-diverging inlet 427 with an
annular throat 431. The forwardly facing converging portions of the
side walls 432 of outer liner 420 are shaped to define an annular
converging-diverging inlet 434 with an annular throat 435. A
plurality of fuel nozzles 436 are circumferentially spaced about
both inlets 427 and 434 so that fuel dsscharged rearwardly
therefrom forwardly of the throat 431 and 435 will pass axially
through the throat 431 and 435 to pump air therewith into the
liners 419 and 420. The nozzles 436 are connected to the fuel
source through a heat transfer coil 438 positioned in combustion
chamber 416 just forwardly of exhaust nozzle 414.
The main cowling tube 305 defines a diverging inlet duct 425
forwardly of compressor stage 301 and a converging exhaust opening
426 rearwardly of the exhaust nozzle 414 of the main thrust stage
304. Since the cowling tube 305 is larger in diameter than any of
stages 301, 302 or 304, a bypass duct 428 is provided along the
length of engine 300 outside of stages 301, 302 and 304. A cone
member 429 is positioned in the exhaust opening 426 with its
forwrdly facing tapered end 430 projecting within flange 412. The
converging portion of tube 305 at exhaust opening 426 defines a
bypass air inlet duct 431 with flange 415 and member 429 defines an
inner air inlet duct 432 with flange 412.
OPERATION OF THIRD ENGINE INSTALLATION
Engine 300 is started similarly to engine 200. First, the heating
coils 345 are supplied with electricity to heat same. This also
heats the air within the annular combustion chamber 334 in the
vicinity of each unit 310 to a temperature sufficient to ignite the
fuel as with unit 10. It is also to be understood that coils 345
may extend completely around the rings 311 and 312 to achieve the
same result.
When the desired temperature is reached, fuel under pressure is
supplied to the low pressure fuel nozzle 329 of each unit 310. The
inlet pressure is sufficiently low to not open valves 338 so that
no fuel is supplied to chamber 334 from the nozzles 332 of ring
manifold 331. The fuel is ejected from the low pressure nozzles 329
in small streams at high velocity axially through the throat 318 of
annulus 314 and into combustion chamber 334. This causes air to be
drawn into chamber 334 with the fuel through throat 318 by the jet
pumping influence of the fuel. When the fuel reaches the heated air
in chamber 334, it ignites to starts combustion. The additional
fuel and air entering chamber 334 sustains the combustion once it
has started and the heat of combustion maintains the proper
operating temperature in the chamber 334 thus allowing the coils
345 to be shut off.
The exiting exhaust gases from the exhaust nozzle 321 pump
additional air into the combustion chamber 376 of the first power
unit 370 via the inlet 364, bypasses 359 and 360, and throat 375 of
inlet 374 because of the jet pumping action of the gases in
combination with the throat 375 of unit 370. This also draws
additional air into the throat 318 of the compressor stage 301. A
portion of the exhaust gases is trapped by the scoops 349 of the
units 310 to pressurize the bleed tubes 346 and force these gases
rearwardly out of ports 351 and struts 330. The jet pumping action
of the exiting gases from the ports 351 forces additional air into
the combustion chamber 334 to pressurize same and support
combustion.
The exhaust gases from the compressor stage 301 passing into the
chamber 376 of the first power unit 370 heats same to fuel ignition
temperature whereupon fuel is sprayed from nozzles 381 into chamber
376 to start combustion within this unit. The exiting exhaust gases
from the nozzle 368 of power unit 370 creates a jet pump effect as
it passes through the throat 392 of the second power unit 385 to
draw air into the combustion chamber 400 from the central passage
357 of the tubular section 355 and from the bypass duct 428 through
the inlet passages 394 and 395 to support combustion. This also
draws additional air into the front of engine 300 to further
pressurize the inlet to units 310. Once combustion chamber 400 is
pressurized, the fuel is sprayed therein by fuel nozzles 402 to
start combustion.
The exhaust gases from the second power unit 385 are injected
axially through the inlet 408 of the main thrust stage 304 to
pressurize same from the jet pump action drawing air through inlet
ducts 410 and 411 from the central passage 387 of inner tubular
section 386 and from the bypass duct 428. Once the combustion
chamber 416 is pressurized, fuel is sprayed therein from fuel
nozzles 421 to start combustion.
As the exhaust gases from the main thrust stage 304 passes through
the exhaust opening 426 in the cowling tube 305, they exert a jet
pumping action drawing air through the bypass duct 428 and the
central passage 403 of the tubular section 404 thus drawing more
air into the inlet duct 425 and further pressurizing the stages
301, 302 and 304.
When the velocity of the engine 300 with respect to the ambient air
is sufficient to sustain combustion pressure from the ram effect,
control means (not shown) causes the valves 336 to shut off fuel
flow to nozzles 329 and to open valves 339 to supply fuel to
nozzles 332 since the jet pumping action of units 310 is no longer
needed.
FOURTH ENGINE INSTALLATION
Referring now to FIG. 12, the fourth embodiment of the invention is
an engine 500 which has a jet pumping action directed from the
center of the engine outwardly. Engine 500 includes a compressor
stage 501, an intermediate stage 502 and a main thrust 504
concentrically mounted about the centerline CL-5 of the main
cowling tube 505.
The compressor unit 501 has an open duct 510 centrally located in
cowling tube 505 at the forward end thereof. Duct 510 has a tubular
wall 511 defining a cylindrical inlet passage 512 and with an
annular projection 514 at the rear end of passage 512 defining a
throat 515 and a combustion chamber 516 therebehind. Combustion
chamber 516 is terminated by the wall 511 converging to form an
exhaust nozzle 518 with an elongated cylindrical exhaust duct 519
extending through the intermediate stage 502 seen in FIG. 15.
A fuel injection assembly 520 similar to assembly 20 of unit 10 is
positioned in inlet passage 512 so that the fuel nozzle 521, in its
forward retracted position, is positioned ahead of throat 515 so
that the fuel is sprayed axially therefrom through throat 515 into
combustion chamber 516 and draws air into the chamber 516 similarly
to that described hereinabove. The nozzle 521 may be made to extend
through throat 515 similar to the assembly 20 for unit 10. The
incoming fuel to assembly 520 is preheated in a heat transfer coil
517.
A preheater coil 522 is positioned in combustion chamber 516
similarly to coil 61 in unit 10. This heats the air in chamber 516
to start combustion and also preheats the fuel.
The intermediate stage 502 includes an open ended duct 530 with a
tubular wall 531 positioned concentrically about duct 510 of stage
501. Wall 531 has an inwardly projecting annular section 532 which,
together with an outwardly projecting annular section on duct 510,
forms a converging-diverging annular inlet passage 534 to
combustion chamber 538. Chamber 538 is provided with a compound
annular burner can assembly 539 with annular cone shaped inner and
outer burner shroud liners 540 and 541 respectively. The forwardly
facing converging portions of side walls 542 of inner liner 540 are
shaped to define an annular converging-diverging inlet 544 with an
annular throat 545. The forwardly facing converging portions of the
side walls 546 of outer liner 541 are shaped to define an annular
converging-diverging inlet 548 with an annular throat 549. A
plurality of fuel nozzles 550 are circumferentially spaced about
both inlets 544 and 548 so that fuel discharged rearwardly
therefrom forwardly of the throats 545 and 549 will pass axially
through the throats 545 and 549 and pump air therewith into the
liners 540 and 541. The nozzles 550 are connected to the fuel
source through a heat transfer coil 551 positioned in the
combustion chamber 538 to preheat same.
The duct wall 531 has an inwardly tapering section 552 behind the
combustion chamber 538 to form a converging exhaust nozzle 554 with
a cylindrical exhaust duct 555 extending through the main thrust
stage 504 and concentrically about the duct 519 of stage 501. Duct
519 terminates within duct 555 in FIG. 12.
The main thrust stage 504 includes a duct tube 560 with a tubular
wall 561 extending forwardly to the inlet ends of the stages 501
and 502 and concentrically about the duct tube 530 of stage 502.
Wall 561 has an inwardly projecting annular section 562 which, in
combination with an outwardly projecting annular section 564 on
wall 531, forms a converging-diverging annular inlet passage 565
about stage 502 to the combustion chamber 566. This chamber, like
chamber 538 of stage 502, is provided with a compound burner can
assembly 568 with annular cone shaped inner and outer burner shroud
liners 570 and 571 respectively. The forwardly facing converging
portions of side walls 572 of inner linear 570 are shaped to define
an annular converging-diverging inlet 574 with an annular throat
575. The forward facing converging portions of the side walls 576
of outer liner 571 are shaped to define an annular
converging-diverging inlet 578 with an annular throat 579. A
plurality of fuel nozzles 580 are circumferentially spaced about
both inlets 574 and 578 so that fuel discharged rearwardly
therefrom forwardly of the throats 575 and 579 will pass axially
through the throats 575 and 579 and pump air therewith into the
liners 570 and 571. The nozzles 580 are connected to the fuel
source through a heat transfer coil 581 positioned in the
combustion chamber 566 to preheat same.
Duct wall 561 tapers inwardly after chamber 566 to form a
converging exhaust nozzle 582 and a cylindrical exhaust duct 584
concentric about duct 555. It will be noted that duct 555
terminates within duct 584.
The cowling tube 505 has an outwardly flaring inlet wall section
585 extending from the vicinity of the forward end of combustion
chamber 566 of stage 504 forward of the inlets to stages 501, 502
and 504 to define a diverging inlet 586. A cylindrical wall section
588 encircles the combustion chamber 566 of start 504 and an
inwardly tapered wall section 589 joins with the rear end of
section 588 to extend past the end of duct 584 of stage 504 and
form a converging discharge 590.
The intermediate stage 502 and the main thrust stage 504 are
provided with regenerative compression units 600 and 601
respectively. The unit 600 includes an annular passage 602 which is
connected to an annular opening 604 in the duct wall 531 in the
vicinity of the rear of combustion chamber 538. A forwardly facing
intake 605 is provided at opening 604 that projects within duct 530
to direct a portion of the escaping exhaust gases from the
combustion chamber 538 through opening 604 into the passage 602 and
forwardly therealong.
A plurality of radially extending rear injection struts 610 are
provided between the duct wall 511 and the duct wall 531. The
struts 610 are equally spaced circumferentially about the wall 511
and lie in a transverse plane through the engine just forwardly of
the inlet passage 534. A bore 611 as seen in FIG. 14 longitudinally
extends through each strut 610 and communicates with the passage
602 through opening 612 seen in FIG. 15 in duct wall 531. A
plurality of rearwardly directed nozzle passages 614 connect with
bore 611 to inject the exhaust gases in passage 602 rearwardly
through inlet passage 534. A plurality of side nozzle passages 615
also communicate with bore 611 to inject the exhaust gasses in
passage 602 rearwardly toward inlet passage 534 and outwardly from
strut 610.
A plurality of radially extending front injection struts 620 are
provided between the duct wall 511 and the duct wall 531. The
struts 620 are equally spaced circumferentially about the wall 511
and lie in a transverse plane through the engine a prescribed
distance a forwardly of rear struts 610. The struts 620 are
staggered with respect to struts 610 as best seen in FIG. 13. A
bore 621 as seen in FIG. 14 longitudinally extends through each
strut 620 and communicates with the passage 602 through opening 622
seen in FIG. 15 in duct wall 531. A plurality of rearwardly
directed nozzle passages 624 connect with bore 611 to inject the
exhaust gases in passage 602 rearwardly toward inlet passage 534
and outwardly from strut 620.
The discharging exhaust gases from the side nozzle passages 615 in
the rear struts 610 and from the side nozzle passages 625 in the
front struts 620 overlap so as to set up a barrier layer around the
inlet passage 534 to prevent the exhaust gases in the combustion
chamber 538 from backing out through the inlet passage 534 during
combustion. It will also be noted that the exhaust gases discharged
from struts 610 and 620 will force enough fresh air through the
inlet passage 534 to support combustion, especially in combination
with the jet pumping action of the discharging exhaust gases from
the compressor unit 501.
The unit 601 as seen in FIG. 12 includes an annular passage 630
which is connected to an annular opening 631 in the duct wall 561
in the vicinity of the rear of combustion chamber 566. A forwardly
facing intake 632 is provided at opening 631 that projects within
duct 560 to direct a portion of the escaping exhaust gases from the
combustion chamber 566 through opening 631 into the passage 630
between the wall 630 and duct wall 561 and forwardly
therealong.
A plurality of radially extending rear injection struts 635 are
provided between the duct wall 531 and the duct wall 561. The
struts 635 are equally spaced circumferentially about the wall 531
and lie in a transverse plane through the engine just forwardly of
the inlet passage 565. A plurality of radially extending front
injection struts 641 are provided between the duct wall 531 and the
duct wall 561. The struts 641 are equally spaced circumferentially
about the wall 531 and lie in a transverse plane through the engine
a prescribed distance "b" forwardly of rear struts 635. The struts
641 are staggered with respect to struts 635 as best seen in FIG.
13. The struts 635 and 641 have a construction similar to those in
FIG. 14 with a central bore communicating with passage 630,
rearwardly directed nozzle passages and side nozzle passages.
The discharging exhaust gases from the struts 635 and 641 perform
similarly to the struts 610 and 620 so as to set up a barrier layer
around the inlet passage 565 to prevent the exhaust gases in the
combustion chamber 566 from backing out through the inlet passage
565 during combustion. It will also be noted that the exhaust gases
discharged from struts 635 and 641 will force enough fresh air
through the inlet passage 565 to support combustion, especially in
combination with the jet pumping action of the discharging exhaust
gases from the intermediate stage 502.
It is to be understood that the intakes 605 and 632 to the
regenerative compression units 600 and 601 may be located at
different points within combustion chambers 538 and 565. Further,
the location and number of struts 610, 620, 635 and 641 may be
varied. The operating fuel pressure may be provided by pumps 650
driven by the heated fuel passing from the coils 517, 551 and 581
as seen in FIG. 12.
This engine is started similarly to the previous embodiments. The
primary jet pumping action is performed by the escaping exhaust
gases from the stages 501, 502 and 504 and air is drawn into the
engine starting from the inside and moving outwardly. Additionally,
a portion of the exhaust gases from the intermediate stage 502 is
fed back through its inlet passage 534 by the regenerative
compression unit 600 to force additional air through passage 534.
Also, a portion of the exhaust gases from the main thrust stage 504
is fed back through its inlet passage 565 by the regenerative
compression unit 601 to force additional air through passage
565.
It is to be understood that the fuel injection assembly 20 may be
interchanged with the assembly 335 without departing from the scope
of the inventive concept. Moreover, it is to be understood that any
of the engines may be equipped with bypass air throttling means as
illustrated for engine 200 and that those engines not having air
bleed tubes in the compressor stage may be so equipped. A plurality
of bleed tubes may be used in lieu of the tube 90 for unit 10.
While specific embodiments of the invention have been disclosed
herein, it is to be understood that full use of modifications,
substitutions, and equivalents may be made without departing from
the scope of the inventive concept.
* * * * *