FR2705736A1 - Thrust nozzle for reaction propulsion with fastening elements. - Google Patents

Abstract

a) Thrust nozzle for jet propulsion with fixing elements ". b) Nozzle characterized in that the fixing elements are arranged like a grid in rows spaced from each other between the supporting structure and the wall of the nozzle, and are assembled with the wall of the nozzle respectively in an element receiver (10), while at least a majority of the fastening elements are held in the element receiver (10) being able to slide longitudinally in the direction R of the rows with respect to the wall of the nozzle, with play transversely to the direction of the rows, and the wall of the nozzle is fixed in places vis-à-vis the supporting structure, against transverse displacement with respect to the direction (R) of the rows or in that direction.

Description

"Thrust nozzle for propulsion by reaction with ele-

  The invention relates to a thrust nozzle for propulsion by reaction with at least one nozzle wall on the hot gas side which is connected to a bearing structure via a plurality of fasteners. The thrust nozzle is described in DE 41 15 403 A. For future reusable space planes, rocket-ramjet engines with different propulsions per reaction are provided. and a simple possibility of switching between modes

  operating systems, thrust nozzles of cross-section

  Rectangular dirty are particularly indicated. The

  Such thrust nozzles are exposed to pressure forces and high thrust jet temperatures. Unlike the thrust nozzle walls of circular cross section, the pressure forces

  give birth in the flat walls of the recom-

  tangular to high bending moments. These couples of

  bending and thermal expansion can consequently

  cause warping or deformation

  in the thrust nozzle, which endanger a func-

  correct configuration of the nozzle. In order to avoid tensions in the structure of the plates which are strongly heat-stressed and generally actively cooled, because the thermal expansion is prevented, it is proposed in DE 41 15 403 A1 to elastically connect to a structure. carrier, by means of small holding hooks, the conductive layer of heat

  in which small cooling tubes are inserted

  while between the heat conducting layer and this supporting structure, a sliding layer is introduced to allow the conductive layer of the

  heat to move parallel. As a layer of

  Ceramic granulate is provided which on the one hand must transmit the pressure forces in the carrier structure and on the other hand tolerate the deformation of the heat conductive layer caused by the temperature. The connection between the heat-conducting layer and the supporting structure is thus effected both via the hook-shaped holding elements and also via the diaper.

slip.

  "From there the purpose of the invention is to

  create a thrust nozzle with an inde-

  formable of the aforementioned type, which remains to a large extent free of deformations in the operating conditions and avoids tensions in the wall of the nozzle because of

  that thermal expansion is prevented. In addition, a

  Reliable mechanical range must be guaranteed between the structure

carrier and the wall of the nozzle.

  This object is achieved, according to the invention, in that the fastening elements are arranged between the structure

  carrier and the wall of the nozzle in the manner of a

  drilled in rows spaced from each other, and are assembled with the wall of the nozzle respectively in a receiver elements by transmitting the pressure forces, while at least a majority of the fasteners is held in the receiver of elements in

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  being able to slide longitudinally with

  to the nozzle wall in the direction of the rows while being held with clearance transverse to this direction, and the nozzle wall is fixed in locations relative to the supporting structure

  against a displacement transverse to the direction

  rows and in the row direction.

  The arrangement according to the invention has the advantage

  to guarantee high form fidelity of the nozzle wall under the operating conditions, thanks to the relatively rigid connection of the nozzle wall to

  the supporting structure perpendicular to the plane of the pa-

  king, without causing tensions because the

  thermal expansion is prevented. Transmission of ef-

  high pressure gases that are absorbed by the wall of the nozzle, and compensation for thermal expansion

  different between the wall of the nozzle and the structure

  are then carried out via the elements

  of fixation. An additional functional intermediate layer

  For the transmission of gas pressure forces or for the compensation of the different thermal expansion, this becomes unnecessary. Unambiguous precise fixing in position of the wall of the nozzle relative to the supporting structure, results from the fixing in places of the wall of the nozzle relative to the supporting structure

  thanks to the coupling transmitting the pressure

  be the wall of the nozzle and the supporting structure. Thanks to a certain spacing between the wall of the nozzle and the support structure because of the fastening elements placed

  between them, a thermal insulation effect is obtained between

  be the wall of the nozzle and the supporting structure for

  avoid an inadmissible heating of the structure

Teuse.

  An embodiment of the advantageous coupling for re-

  bind in a precise position the wall of the nozzle to the

  structure, with the possibility of expansion

  The preferred embodiments of the invention, according to which: the fixing of the wall of the nozzle transversely with respect to the direction (R) of the rows, is effected by means of a

  number of fasteners in a row, likely to

  able to slide longitudinally and which, transversally

  relative to the direction (R) of the rows, are guided essentially without play .; the fixing of the wall of the nozzle in the direction (R) of the rows is carried out thanks to a certain number of fixing elements which can slide transversely with respect to the direction (R) of the rows and which are maintained essentially without play in the direction (R) of the rows .;

  - fastening elements capable of sliding

  towards the direction (R) of the rows

  lie on a grid axis (G ') extending transversally

  in relation to the direction (R) of the rows .;

  - the rows are spaced parallel to each other

  very. For nozzle walls that extend from both

  side of the throttle of a converging thrust nozzle

  divergent, an achievement is particularly

  is lying; according to the latter, the wall of the nozzle is bent in the shape of a V while the fastening elements are provided in the wall zones on both sides of the curvature and that the direction of the rows is perpendicular to the axis of the

  curvature. Due to the arrangement of the fixing elements

  in the flat wall areas on both sides of the curvature, the wall of the nozzle is fixed transversely to the constriction or to the axis of curvature without a separate attachment by

fixation is necessary.

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  For optimum adaptation of the nozzle wall attachment to the flow conditions in the

  nozzle, which determines the thermal and mechanical loading

  the thrust nozzle of the nozzle wall is advantageously characterized in that: the direction (R) of the rows is oriented approximately in the direction of flow (S) of the thrust nozzle;

  the fixing points of the wall of the nozzle are preferably

  seen in the row direction roughly in the area

  the cross section (Q) of the nozzle.

  According to advantageous configurations of the invention

  which contribute to simplify the construction of the thrust nozzle:

  - the rows are evenly spaced from each other

  very.; the fastening elements are spaced uniformly from one another in the direction (R) of the rows; - the element receptors are reported on the structure side

  carrier on the wall of the nozzle at intersec-

  O20 tion of a uniform imaginary grid.

  Screwing the fastening elements with the supporting structure is favorable for mounting and

the repair.

  According to other embodiments of the invention,

  The construction elements are advantageous from the point of view of construction. The fastening elements are screwed together with the supporting structure. - The element receptors are constituted respectively of two holding claws arranged parallel to one another, and which surround a mushroom-shaped head

  fasteners by forming a sliding fit

  health: - the element receptors are formed on the wall of the nozzle

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  the fastening elements are formed from a plate

  fastening element connected to the base structure and having protruding elements on the side of the wall of the nozzle.

  to allow assembly with the wall of the nozzle.

  the supporting structure constitutes the casing of the nozzle.

  The invention will be explained in more detail below.

  FIG. 1 is a perspective view in partial section of a Laval thrust nozzle with a rectangular channel cross-section for a reactor,

  FIG. 2a is a sketch of a side wall

  2b is a perspective view of a wall of the V-shaped curved nozzle; FIG. 3a is a cross-section according to FIG. 1 of the flat wall of the nozzle screwed with the nozzle; nozzle casing; FIG. 3b shows part of the nozzle of

  Figure 1 in the zone of the transverse section

  0 narrow narrow with the curved wall V-shaped in longitudinal section, - Figure 4a is a cross section of the

  thrust nozzle in the securing zone of an element se-

  In FIG. 3a, FIG. 4b is a cross section of FIG.

  thrust nozzle in the securing zone of an element se-

  In FIG. 3b, FIG. 5a is a schematic sketch of the

  plane side wall of the nozzle with the indication of

  freedom of movement, and

  FIG. 5b is a diagrammatic view in FIG.

  pective of the V-shaped curved wall of the nozzle with

  the indication of the degrees of freedom of movement.

  FIG. 1 shows a Laval thrust nozzle 1, also known as a convergent / divergent thrust nozzle, for a reactor not shown in greater detail. To allow the connection of the thrust nozzle 1 to a reactor, the latter may be flanged on a connecting tube 2 of the thrust nozzle 1. In operation, the thrust nozzle 1 is traversed axially by the throttle according to the direction of flow S. In

  downstream, the thrust nozzle 1 opens into a ramp of ex-

  pansion 3 which increases the maximum thrust that can be achieved

  holding the thrust nozzle 1 or the reactor. The channel cross section of the connecting tube 2 is

  transforms into a rectangular cross section cor-

  corresponding to the cross-section of the channel of the thrust nozzle 1. The casing 4 of the thrust nozzle 1 located with respect to the direction of flow S between the connecting tube 2 and the expansion ramp 3 serves, in as bearing structure 4 ', to absorb the pressure forces of the gases. To increase the rigidity of the casing 4 of the nozzle and to increase the cooling surface, the housing 4 of the nozzle is provided to the outside with a plurality of rib 5 intersecting. Inward, that is to say towards the flow channel K, the structure

  carrier 4 'is essentially flat. The channel of

  K of rectangular section is limited in space by the walls 6 of the nozzle coupled to the casing 4 of the nozzle 5. To protect them from overheating, the walls 6 of the nozzle are passed inside, in the vicinity of the channel, by cooling channels 7. The cooling channels 7 (see also FIGS. 2b, 3a, 4a and 5b)

  are during operation fed with fluid

  cooling by tubular conduits not shown

  more in detail. Two flat nozzle walls 6a and 6b,

  parallel to each other, limit

  Usually the flow channel K, while a top wall 6c, bent V-shaped, limits the flow channel upwards. Two flat walls 6d and 6e,

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  contiguous and forming a V, define the flow channel K downwards. The curvatures, conditioned by the V-shape, of the upper and lower wall regions of the nozzle extend parallel to a certain distance from each other and are, with respect to the flow, at the same channel depth and thus give the flow channel K the typical convergent / divergent transition

  of a Laval nozzle. The upper and lower walls

  res 6c or 6d and 6e apply sealingly by their lateral side edges 8 against the side walls 6a

and 6b.

  Figure 2a shows the opposite side to the flow channel K of the wall 6a placed to the right with respect to the direction S of the flow. For its adaptation to the V-shaped evolution of the upper wall 6c of the nozzle, the wall 6a has a notch 9 V-shaped.

  see also the claw shaped conformation and the

  Grid partition of the elements receivers 10 side

  bearing structure on the wall 6a of the nozzle. One

  identical training and a similar provision of receivers

  elements 10 is visible on the structure side

  carrier of the wall 6c of the nozzle in Figure 2b.

  As can be seen in detail in FIGS. 3a and 3b as well as 4a and 4b, each nozzle wall 6a, 6b,

  6c, 6d and 6e is coupled with the carrier structure 4 'ad-

  The nozzle wall 6, in its extent parallel to the channel-side plane surface of the carrier structure 4 ', is spaced from this surface by the plurality of fastening elements 11.

  fastening elements 11 placed between them. For the trans-

  mission in the carrier structure 4 'efforts to

  of the gases captured by the wall 6 of the nozzle, the

  fasteners 11 are on the one hand screwed to the structure

  4 'and respectively coupled in a receiver.

  element 10 of the wall 6 of the nozzle while being

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  movable longitudinally with respect to this receiver and transmitting the pressure forces. The fastening elements 11 are made in the form of mushrooms on a fixing plate 12. The fastening elements 11 are arranged on the fixing plate 12 corresponding to the position of the elements receivers 10 on the mounting plate 12.

  wall 6 of the nozzle. The fastening elements 11 extend

  perpendicularly to the fixing plate 12 or to the wall 6 of the nozzle. On the side of the wall of the nozzle, the fastening elements 11 end with a

  head 13 shaped skate with heels 14 extending la-

  laterally, these heels 14 being respectively embraced by two element receiver holding claws 15 to allow guiding in longitudinal displacement of a fastening element 11. As can also be seen on

  Figures 2a and 2b, two holding claws 15 are res-

  respectively reported parallel to each other and at a distance from each other on the wall 6 of the

  nozzle on the supporting structure side, thereby forming a

  of elements 10. Each holding claw 15 thus forms

  if with the wall 6 of the nozzle a groove 16 extending

  in the longitudinal direction, whose transverse height

  at the level of the wall 6 is given at the height of the

  lon 14 received so as to be able to slide longitudinally

  in this groove, so that transverse displacements

  in relation to the plane of the wall 6 of the nozzle are

excluded to a large extent.

  As can be seen in FIGS. 2a and 2b, the arrangement of the element receptors 10 on the walls of

  nozzle 6 is made at grid points 11 which result in

  attempt to cross two groups of imaginary parallel G grid axes. The grid angle has intersecting axes G, is about 850. For the representation of the grid arrangement of the receiving elements 10 on the side of the wall 6 facing the supporting structure 4 ',

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  the walls 6a and 6c of the nozzle are shown on the

  2a or 2b in the disassembled state, that is to say without

  For uniform distribution of the charge, the receivers of elements O10, with the exception of those placed in the vicinity of the exchanger 9, are arranged in rotation.

  lying parallel to each other. Inter-

  valle a is then constant from one row to another.

  The interval b of the element receivers 10 of a row is also constant. In the case of flat walls 6a, 6b, 6d, 6e (see FIG. 2a), an element receiver 10 'of a row is respectively oriented, unlike the

  other receivers of elements 10 of the same row, trans-

  versalement relative to the direction R of the row which is approximately parallel to the flow direction S, and lying on a common gate axis G '. Because

  the grooves 16 of the element receptors 10 'are

  transversely to the direction R, thus in the direction of the gate axis G ', the fastening elements 11' coupled to these element receivers 10 'are guided so as to be able to move transversely relative to the direction R, which results in a fixing in position of the wall 6 of the nozzle relative to the carrier structure 4 'in the direction R. The distance C2 between the parallel sides of two holding claws 15' of the element receivers 10 transversely oriented, is chosen so that the fastening elements 11 'movable longitudinally in these

  claws, are guided essentially without lateral play.

  Unlike flat walls 6a, 6b, 6d and 6e

  of the nozzle, in the case of the bent wall 6c, the

  Transversely oriented element members 10 'for fixing the wall 6c in the direction R are suppressed because, due to the V-shape of the wall 6c and the coupling

  with the carrier structure 4 'via the elements

  11, a fastening in the direction of the rows is obtained in the area of the curvature as

  is visible. in Figure 3b. A free possibility of di-

  However, the wall 6c in the direction R, leaving the curvature, remains maintained because of the longitudinally sliding coupling. For fixing the wall 6 of the nozzle relative to the support structure 4 'transversely to the direction R, a number of fastening elements 11'

  are guided so that they can move longitudinally-

  10 'elements receivers with minimal lateral play. The corresponding element receptors '10' are arranged along a common grid axis G "which extends in the direction R, close to the edge for the flat walls 6a, 6b, 6d, 6e and approximately in the medium for the bent wall 6c (see Figures 2b and 3a) Correspondingly, the gap C2 between the parallel sides of two holding claws 15 "of these element receptors 10" is, as already in the case of transversely oriented element receptors 10 ', smaller than the distance Cl of the sides in the other element receivers 10 which are guided with a lateral clearance, the degrees of mobility resulting from this

  lateral clearance of the fastening elements 11 with respect to the

  element receivers 10 are represented symbolically by

  arrows P2 in FIGS. 3a and 4a which show

  respectively in cross-section with respect to the direction R. In FIGS. 5a and 5b, the arrows Pi and P2

  respectively indicate the degrees of freedom for the com-

  Expansion thought on the flat wall 6a or on the bent wall 6c, degrees of freedom that result from the previously described fastenings of the walls 6 on the basis of

  the orientation of the element receptors 10, 10 ', 10 "

  towards or parallel to the direction R, and because of the importance of lateral play. The arrows Pi give a possibility of expansion for the wall 6 because of the

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  possibility of longitudinal sliding of the elements of

  11, while the arrows P2 give a possibility of

  due to the lateral play of the fastening elements 1il in the element receivers 10. The same applies to the arrows P1 and P2 in FIGS. 3a, 3b, 4a

and 4b.

R E V E N D I CATIONS

  1) reactor thrust nozzle with at least one hot gas-side nozzle wall which is connected to a carrier structure via a plurality of fasteners distributed in the plane of the wall, thrust nozzle characterized in that the fastening elements (11) are arranged in the manner of a grid in rows spaced apart from each other between the structure

  carrier (4 ') and the wall (6) of the nozzle, and are

  with the wall (6) of the nozzle respectively in a receiver of elements (10), while at least a majority

  fasteners (11) are held in the receiver

  element (10) being able to slide longitudinally

  longitudinally in the direction R of the rows with respect to the wall (6) of the nozzle, with clearance transverse to the row direction, and the wall (6) of the nozzle is fixed in locations with respect to the structure carrier (4 ') against a transverse displacement relative to the

  direction (R) of the rows or in that direction.

  2) thrust nozzle according to claim 1, characterized in that the attachment of the wall of the nozzle

  transversely to the direction (R) of the

  are carried out by a number of

  longitudinally displaceable and which, transversely to the row direction (R), are guided substantially without play. 3) A thrust nozzle according to claim 1 or claim 2, characterized in that what fixing of

  the wall (6) of the nozzle in the direction (R) of the

  are carried out thanks to a certain number of elements of

  fastener (11) which can slide transversely

  port to the direction (R) of the rows and which are maintained

  essentially without play in the (R) direction of the rows.

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  4) thrust nozzle according to claim 3,

  characterized in that the fastening elements (11)

  able to slide transversely with respect to the direction (R) of the rows are located on a grid axis (G ') extending transversely to the direction

(R) rows.

  ) Thrust nozzle according to one of the preceding

  claims, characterized in that the rows are

  paced parallel to each other.

  6) thrust nozzle according to claim 1 or claim 2, characterized in that the wall (6) of

  the nozzle is bent in the shape of a V and that the elements

  fastening elements (11) are provided in wall areas on both sides of the curvature, while the direction (R)

  rows is perpendicular to the axis of curvature (A).

  7) Thrust nozzle according to one of the preceding

  claims, characterized in that the direction (R) of the

  rows is oriented roughly in the direction of flow.

  (S) of the thrust nozzle (1).

  8) Thrust nozzle according to one of the preceding

  claims, characterized in that the fixing points

  the wall (1) of the nozzle are provided in the di-

  rows in the area of the section

cross section (Q) of the nozzle.

  9) Thrust nozzle according to one of the preceding

  claims, characterized in that the rows are

  paced uniformly from each other.

  ) Thrust nozzle according to one of the preceding

  claims, characterized in that the elements of

  fastening (11) are uniformly spaced from one another

in the direction (R) of the rows.

  11) Thrust nozzle according to one of the preceding

  claims, characterized in that the receivers

  of elements (10) are reported on the carrier structure on

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  the wall (6) of the nozzle at the points of intersection of a

uniform imaginary grid.

  12) Thrust nozzle according to one of the preceding

  claims, characterized in that the fixing

  fastening elements (11) are screwed together with the

* (4 ').

  13) Thrust nozzle according to one of the preceding

  claims, characterized in that the receivers

  of elements (10) consist respectively of two holding claws (15) arranged parallel to each other.

  the other, and surrounding a mushroom-shaped head (13)

  securing fastening elements (11) forming a sliding fit. 14) Thrust nozzle according to one of the preceding

  claims, characterized in that the receivers

  elements (10) are formed on the wall (6) of the nozzle.

  ) Thrust nozzle according to one of the preceding

  claims, characterized in that the elements of

  fastening (11) are formed from a fixing plate (12) connected to the base structure (4 ') and having on the side of the wall of the nozzle projecting elements (11).

  to allow assembly with the wall (6) of the nozzle.

  16) Thrust nozzle according to one of the preceding

  claims, characterized in that the structure

  (4 ') constitutes the casing (4) of the nozzle.