U.S. patent number 3,782,118 [Application Number 05/315,984] was granted by the patent office on 1974-01-01 for regeneratively cooled thrust gas generator construction and method of making same.
This patent grant is currently assigned to Messerschmitt-Bolkow-Blohm Gesellschaft mit beschrankter Haftung. Invention is credited to Karl Butter, Helmut Dederra, Michael Kaufmann.
United States Patent |
3,782,118 |
Butter , et al. |
January 1, 1974 |
REGENERATIVELY COOLED THRUST GAS GENERATOR CONSTRUCTION AND METHOD
OF MAKING SAME
Abstract
A thrust gas generator includes combustion chamber and a thrust
nozzle and as a plurality of longitudinally arranged and
circumferentially spaced capillary tubes which form closed canals
for the cooling medium, especially a liquid. A metallic layer
particularly one which is applied by electroplating, joins the
capillary tubes to form a pressure-tight combustion chamber. The
electroplated metal is applied to positively embrace the capillary
tubes at their radially outward portions or their radially inward
portions to bridge the spaces between the tubes. The tubes are
shaped so that they have a substantially constant cross section
over major portion of their length and they may include a variable
cross section in the thrust nozzle or neck portion.
Inventors: |
Butter; Karl (Munich,
DT), Kaufmann; Michael (Neubiberg, DT),
Dederra; Helmut (Ottobrunn, DT) |
Assignee: |
Messerschmitt-Bolkow-Blohm
Gesellschaft mit beschrankter Haftung (Ottobrunn bei Muenchen,
DT)
|
Family
ID: |
23226963 |
Appl.
No.: |
05/315,984 |
Filed: |
December 18, 1972 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
62448 |
Aug 10, 1970 |
|
|
|
|
Current U.S.
Class: |
60/260; 165/169;
60/267 |
Current CPC
Class: |
F02K
9/64 (20130101) |
Current International
Class: |
F02K
9/64 (20060101); F02K 9/00 (20060101); F02k
011/02 () |
Field of
Search: |
;60/267,39.66,260 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Croyle; Carlton R.
Assistant Examiner: Olsen; Warren
Attorney, Agent or Firm: John J. McGlew et al.
Parent Case Text
This is a streamline continuation, of application Ser. No. 62,448
filed Aug. 10, 1970 now abandoned.
Claims
What is claimed is:
1. A regeneratively cooled thrust gas generator comprising a hollow
tubular wall defining a combustion chamber and a thrust nozzle
having a narrow diameter portion and a diverging portion
terminating in a thrust gas discharge, said hollow tubular wall
being made up of a plurality of longitudinally extending tubes,
each tube forming a closed cooling channel for the flow of a
cooling medium therethrough, and a metallic layer extending between
said tubes at least in the diverging portion of said nozzle and
extending over a portion of the periphery of each tube and bonded
thereto, said metallic layer comprising an electroplated layer
positively embracing the capillary tubes and forming, at least in a
section in the diverging portion of said nozzle, circumferentially
extending wall portions between said tubes of a circumferential
extent at least as great as the diameter of said tubes.
2. A regeneratively cooled thrust gas generator, according to claim
1, wherein said tubes are of substantially constant cross-section
over their entire lengths.
3. A regeneratively cooled thrust gas generator, according to claim
1, wherein said tubes are of substantially constant cross-section
over at least a major portion of their lengths.
4. A regeneratively cooled thrust gas generator, according to claim
1, wherein said tubes are in substantially abutting contact at said
narrow diameter portion of said thrust nozzle.
5. A regeneratively cooled thrust gas generator, according to claim
1, including a hollow terminating ring arranged at the discharge
end, said tubes having inturned end portions at said discharge
extending into and sealed with said terminating ring, said ring
being electroplated with said layer.
6. A regeneratively cooled thrust gas generator, according to claim
1, wherein said tubes are distributed around said nozzle
circumference in said divergent wall portion with the spacing
therebetween increasing with the increasing nozzle diameter toward
said thrust discharge, the spacing between said tubes being
exclusively bridged by electroplated material joining said tubes
together.
7. A regeneratively cooled thrust gas generator, comprising a
hollow tubular wall defining a combustion chamber and a thrust
nozzle having a narrow diameter portion and a diverging portion
terminating in a thrust gas discharge, said hollow tubular wall
being made up of a plurality of longitudinally extending
circumferentially arranged tubes with each tube forming a closed
cooling channel for the flow of a cooling medium therethrough, a
circumferentially extending electroplated metallic layer extending
over a portion of the periphery of said tubes along their lengths
and bonded to said tubes, said electroplated layer with said tubes
comprising said hollow tubular wall and with the electroplated
layer extending between said tubes in the area defining said
diverging portion and defining the only interior wall surface
between said tubes at such location.
8. A regeneratively cooled thrust gas generator, according to claim
7, wherein said tubes are in abutting contact in the area defining
said combustion chamber and said thrust nozzle narrow diameter
portion and wherein at such locations, said electroplated layer
extends around the exterior periphery of said tubes.
9. A regeneratively cooled thrust gas generator, according to claim
7, wherein said tubes are spaced apart in the area defining said
combustion chamber and wherein said electroplated layer forms the
interior wall between the tubes in this area.
Description
SUMMARY OF THE INVENTION
This invention relates in general to the construction and method of
making combustion chambers, and in particular, to a new and useful
regeneratively cooled thrust gas generator including a combustion
chamber thrust nozzle having longitudinally arranged capillary
tubes or similar tubular elements forming closed canals for the
cooling medium especially for a liquid cooling medium and including
a metallic layer which joins the capillary tubes together into a
firm pressure-tight construction and which comprises an
electroplated layer.
In a known design of combustion chamber and/or thrust gas
generators of the regenerative type, the wall to be cooled
comprises capillary tubes with different cross sections which also
vary longitudinally in cross sections. These capillary tubes are
dimensioned and arranged symmetrically about the longitudinal axis
of the combustion chamber in such a manner that they touch each
other laterally along their entire length. In this form of design,
an electroplated layer making contact with the radial outer surface
line of the capillary tubes provides the pressure-tight bonding of
the tubes. However, undesirable deformations of the tubes tend to
cause irrepairable leaks. Such conditions are due to locally
present high temperatures which are produced during the soldering
or welding of the tubes at their lateral points of contact. These
disadvantages are prevented with certainity when using tube bonding
methods which are carried out without heat being supplied. When the
tubes are bonded by an electroplated metal layer, there is an
increase of weight which, as compared with the known soldered or
welded form of construction, is maintained within economically
justified limits by leaving the gaps defined by the peripheral
regions between the radial outer surface lines and the lateral
(linear) point of contact of each two adjacent tubes free of the
layer material when the electroplated layer is applied. To this
end, the gaps are levelled off prior to the application of the
electroplated layer with a low melting filling material which is
electrically conductive at its exposed surface. The filling
material is applied so that there is only line-shaped bonds which
are therefore prone to produce cracks between the capillary tubes
on the one hand and the electroplated layer on the other hand.
The invention is therefore based on the task of developing the
combustion chamber and/or thrust nozzle which is inexpensive to
manufacture, and is characterized by greater static and dynamic
strength against the forces arising from the internal pressure of
the combustion chamber due to the occurring temperature differences
in manufacture or operation, and which is lighter in weight than
the known designs. According to the invention, it is solved by
arranging the capillary tubes around the longitudinally extending
combustion chamber axis and/or thrust nozzle axis with spacings
therebetween being uniformly maintained either over the entire
length of the thrust generator, or at least in defined sections
thereof. A metallic layer, particularly a layer which is applied by
electroplating is arranged to positively embrace the tubes either
at their radially outer or radially inner peripheral regions and
also to bridge the gaps therebetween.
In another form of the inventive construction of combustion chamber
or thrust nozzle which is particularly inexpensive and light in
weight the capillary tubes or tubular elements are formed with
constant cross sections over substantially their entire length and
are dimensioned so that the tubes lie next to each other and
without any spacing therebetween only at the narrowest cross
sections of the thrust nozzle. With such an arrangement not only is
the circumference of the diverging part of the thrust nozzle
covered by the capillary tubes and by the parts of the metallic
layer which is applied by electroplating to bridge the spaces
between them but also the circumference of the combustion chamber
and the convergent part of the thrust nozzle with the exception of
the neck portion thereof.
Because of the intimate bond, which extends over a relatively large
area between the metallic layer and the capillary tubes and the
comparitively high flow velocities of the cooling medium resulting
from the fact that the tubes remain substantially constant in cross
section from the neck of the thrust nozzle to the rear end of the
thrust nozzle, a sufficient cooling is assured in both forms of
construction of the invention.
In accordance with a further feature of the invention, the tubular
elements located at the discharge end of the thrust nozzle are bent
outwardly and are imbedded in the radial outer zone of a stiff
nozzle ring which is electroplated into position when the metallic
layer is applied by electroplating. The radial inner surface of the
ring is not profiled and it is flush with the parts of the metallic
layer which lie within the region of the inner nozzle contour
between the tubular elements. This design brings about two
advantages: First the nozzle terminating ring serves to provide a
stiffening element for the discharge end of the thrust nozzle or
combustion chamber. Secondly, it permits a smooth and even
discharge flow from the combustion chamber or nozzle.
The invention provides also an improved method for manufacturing
the combustion chamber and/or the thrust nozzle, which comprises
providing a combustion chamber and/or thrust nozzle core with an
electrically conductive surface which determines the inner contour
of the combustion chamber and/or thrust nozzle, machining out the
core surface particularly by milling continuous longitudinal
grooves which are separated from one another at least in sections
by bridging portions or lands, inserting suitably formed and shaped
capillary tubes into the grooves between the lands, and applying by
electroplating a metallic layer on the outwardly pointing
peripheral regions of the capillary tubes or shapes and on the
surfaces of the core lands located between the tubular shapes.
Accordingly, it is an object of the invention to provide an
improved method for forming a combustion chamber and/or a thrust
nozzle which comprises forming a core which determines the inner
contour, machinging out the core surface to form longitudinally
extending grooves, inserting individual tubular elements forming
closed longitudinally extending cooling channels within the grooves
and applying electroplating a metallic layer on the outward
peripheral regions of the capillary tubes and the spaces between
the tubes over the core.
A further object of the invention is to provide an improved
combustion chamber construction which includes a wall formed by
longitudinally extending spaced tubular elements forming cooling
medium conduits which are firmly held together in a pressure-tight
manner by a layer of an electroplated metal material which
positively embraces the tubes at their radially inner portions or
radial outward portions, and wherein the tubes are made of
substantially uniform cross sections through out the length and are
either maintained in spaced relationship throughout their lengths,
or are arranged in contacting relationship only at the narrowest
cross section.
A further object of the invention is to provide a combustion
chamber or nozzle construction which is simple in design, rugged in
construction, and economical to manufacture.
The various features of novelty which characterize the invention
are pointed out with particularity in the claims annexed to and
forming a part of this specification. For a better understanding of
the invention, its operating advantages and specific objects
attained by its use, reference should be had to the accompanying
drawings and descriptive matter in which there are illustrated and
described preferred embodiments of the invention .
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an axial sectional view of a combustion chamber
constructed in accordance with the invention;
FIG. 2 is a partial section taken along the line II--II of FIG. 1;
and
FIG. 3 is a section similar to FIG. 1 of another embodiment of the
invention; and
FIG. 4 is a section taken along the line IV--IV of FIG. 3.
GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the invention embodied
therein, in FIGS. 1 and 2, comprises a thrust nozzle device or
thrust gas generating device having a combustion chamber portion 1,
a thrust nozzle portion 2 with a convergent part which is
designated 3 and a neck portion 4 having a divergent part 5. The
entire device is formed by a plurality of longitudinally arranged
capillary tubes 7 which are spaced apart circumferentially and held
in a fixed position by a metallic layer 6 which surrounds the
outwardly extending portions of each tube over a portion of their
peripheries. The layer 6 is applied by electroplating to form a
firm and unified structure.
The capillary tube 7 includes a first portion 9 which is of
substantially constant cross section and extends from the front end
or closed end 30 to the beginning of the converging portion of the
nozzle 4. A second longitudinal section 10 having a cross section
which varies in dimension extends from the converging portion 3 to
the neck portion 4. A further portion 11 extends from the neck
portion 4 to the discharge or open end 32. The tubes 7 have a cross
section in the section 11 which is substantially constant
throughout the length of the section. From the end 30 of the
combustion chamber 1 to the thrust nozzle neck 4, the capillary
tubes 7 touch each other laterally. From the thrust nozzle neck 4
to the discharge end 32 of the thrust nozzle 2, they are separated
from each other by spaces 12 which, because of the fact that the
tube section remains constant, increases rapidly in width with
increasing nozzle diameter. These spacings 12 are bridged in a
pressure-tight manner by parts 13 of the metallic layer which lie
within the contour of the nozzles.
The ends 14 of the capillary tubes 7 at the discharge end 32 are
bent outwardly and are embedded in longitudinal grooves 16 of a
radial outer portion of a stiff nozzle terminating ring 15. The
ring 15 is electroplated together with the metallic layer 6 which
is also applied by electroplating. The nozzle terminating ring 15
has an inner surface 17 which is flush with the part 13 of the
metallic layer 6 which is located between the tubes within the
inner nozzle contour.
In the embodiment shown in FIGS. 3 and 4, there is provided a
combustion chamber or thrust gas generator having a combustion
chamber 31 and a thrust nozzle 32. The thrust nozzle 32 includes a
convergent part 33, a neck 34, and a divergent part 35. The thrust
nozzle according to the embodiments of FIGS. 3 and 4, similar to
that of FIGS. 1 and 2, and comprises a plurality of longitudinally
extending capillary tubes 37 and a metallic layer 36 which is
positively engaged around a portion of the outer periphery of each
tube and which is applied by electroplating. The construction of
FIGS. 3 and 4 differ from that of FIGS. 1 and 2 in respect to the
capillary tubes 37 which have cross sections which are constant
over the entire length thereof. The tubes 37 touch each other in
the region of the thrust nozzle neck 34 are separated from each
other in the divergent thrust nozzle part 35 as well as in the
convergent thrust nozzle 33 and the region of the combustion
chamber 31 by interspaces 42. The interspaces 42 are also bridged
by the parts 43 of the metallic layer 36 which is located within
the region of the inner nozzle contour. The ends of the capillary
tubes 37 are located at their rear end of the thrust nozzle 37 and
they can be embedded in the outer region of a stiff nozzle
terminating ring similar to that of FIGS. 1 and 2 or as indicated
in FIG. 3.
The thrust generator according to the invention can be constructed
with less weight than the known types using the capillary tube
construction, because in contrast to the latter, only the thermally
highly stressed sections of the combustion chamber and/or thrust
nozzle are peripherally covered exclusively by capillary tubes
while the remaining thermally less stressed sections in order to
reduce the weight are peripherally covered only partly by capillary
tubes the interspaces being covered by the metallic layer,
particularly a layer applied by electroplating. As a further
advantage is added that the metallic layer, especially the layer
applied by electroplating, makes contact not only with the radially
outer surface lines of the capillar tubes or shapes, as in the
known case, but surrounds a portion of their peripheries so that at
all mutual points of contact reliable area bonds are assured
between the metallic layer on the one hand and the capillary tubes
or shapes on the other hand.
In the development of the invention, it is proposed to use
capillary tubes or shapes with cross sections which are constant
over the entire length or at least a large part of same. Due to
their lower machining and labor cost, such capillary tubes or
shapes are cheaper in production than the capillary tubes or shapes
used for the construction of the known combustion chambers and/or
thrust nozzles, which for geometric reasons must have variable
cross sections over the entire length or over a large part of same.
This fact has an extremely positive effect on the manufacturing
casts of a combustion chamber and/or thrust nozzle, and such costs
are substantially influenced by the prices of the capillary tubes
or shapes, respectively.
* * * * *