Rocket engine

Abstract

A rocket engine having a thrust chamber bounded by a casing construction with a chamber longitudinal axis. The casing construction includes at least one cooling channel in fluidic connection with a source of a cooling medium. The cooling channel is traversed by a plurality of bridge elements around which the cooling medium flows and which each extend only over a part, in particular a minor part, of the length of the cooling channel measured along the chamber longitudinal axis, and which connect two casing wall pieces, bounding the cooling channel on the inside and on the outside of the casing construction, to one another.

Claims

1. A rocket engine having a thrust chamber bounded by a casing construction with a chamber longitudinal axis, wherein the casing construction includes at least one cooling channel in fluidic connection with a source of a cooling medium, wherein the cooling channel is traversed by a plurality of bridge elements around which the cooling medium flows and which each extend only over a part of the length of the cooling channel measured along the chamber longitudinal axis, and which connect two casing wall pieces, bounding the cooling channel on the inside and on the outside of the casing construction, to one another.

2. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are arranged with, referring to a circumferential direction of the thrust chamber, mutual angular offset in the cooling channel

3. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are arranged with, referring to the chamber longitudinal axis, mutual longitudinal offset in the cooling channel

4. The rocket engine according to claim 1, wherein each bridge element has, in a flow direction of the cooling medium in the cooling channel, an extent which is not more than 20% of the length of the cooling channel measured in the flow direction.

5. The rocket engine according to claim 1, wherein each bridge element has, in a flow direction of the cooling medium in the cooling channel, an extent which is not more than 1% of the length of the cooling channel measured in the flow direction.

6. The rocket engine according to claim 1, wherein the two casing wall pieces are formed of annular wall parts arranged concentrically within one another and separated from one another by a radial annular space, and the cooling channel has in the annular circumferential direction an angular width of at least 180 degrees.

7. The rocket engine according to claim 1, wherein the two casing wall pieces are formed of annular wall parts arranged concentrically within one another and separated from one another by a radial annular space, and the cooling channel has in the annular circumferential direction an angular width of at least 30 degrees.

8. The rocket engine according to claim 7, wherein the cooling channel extends over the entire annular circumference.

9. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are at least one of different shape or of different size.

10. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are of the same shape and of the same size.

11. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are implemented as bridge webs which are longer than they are wide when viewed in a sectional area oriented along the casing wall pieces.

12. The rocket engine according to claim 11, wherein at least a partial number of the bridge webs, when viewed in the sectional area, are oriented with their web longitudinal direction parallel to the chamber longitudinal axis.

13. The rocket engine according to claim 11, wherein at least a partial number of the bridge webs, when viewed in the sectional area, are oriented with their web longitudinal direction at an acute angle obliquely with respect to the chamber longitudinal axis.

14. The rocket engine according to claim 11, wherein at least a partial number of the bridge webs, when viewed in the sectional area, have one of a rectilinear web shape, a curved web shape, or a kinking web shape.

15. The rocket engine according to claim 11, wherein edges of the bridge webs arranged upstream or downstream relative to the flow direction, when viewed in the axial longitudinal section through the chamber longitudinal axis, run perpendicularly to surfaces of the casing wall pieces bordering on the cooling channel

16. The rocket engine according to claim 11, wherein the bridge webs have a trapezium-shaped cross-section in the axial longitudinal section through the chamber longitudinal axis.

17. The rocket engine according to claim 11, wherein, when viewed in the sectional area, the length of the bridge webs is measured in parallel to the chamber longitudinal axis and the width of the bridge webs is measured perpendicularly to the chamber longitudinal axis.

18. The rocket engine according to claim 1, wherein at least a partial number of the bridge elements are produced with the two casing wall pieces in one piece continuously without joints.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is explained in more detail below with the aid of the appended drawings using the example of a rocket engine, in which

[0020] FIG. 1 shows a schematic longitudinal sectional view of a rocket engine;

[0021] FIG. 2 shows a partial longitudinal sectional view of the casing construction of the rocket engine from FIG. 1 along a sectional plane through the chamber longitudinal axis;

[0022] FIG. 3 shows a partial longitudinal sectional view of the casing construction of the rocket engine along the sectional area A-A from FIG. 1; and

[0023] FIG. 4 shows a perspective partial view of a portion of the casing construction of the rocket engine from FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] FIG. 1 shows a rocket engine 10 having a thrust chamber 12 which comprises a combustion chamber 14 and a nozzle 16. The thrust chamber 12 is bounded by a casing construction 18 which extends along a chamber longitudinal axis A. In the casing construction 18 there is formed at least one cooling channel 20 which is in fluidic connection with a source 19 of a cooling medium. The casing construction 18 has casing wall sections 21 and 23 bounding the cooling channel 20 with respect to the axis A radially on the inside and on the outside. In the example shown, the two casing wall sections 21, 23 are formed by annular wall parts arranged concentrically in one another. The cooling channel 20 extends 360 degrees around the chamber longitudinal axis A.

[0025] During the operation of the rocket engine 10 the cooling medium is supplied from the source 19 through a supply line 22 and an inlet distributor 24 to the cooling channel 20, into which it flows in flow direction S (cf. FIGS. 2 to 4). The casing construction 18 and the cooling channel 20 extend from a first end of the thrust chamber 12 which is opposite the nozzle 16 and faces the inlet distributor 24, to a second end of the thrust chamber 12 which is opposite the first end, at which second end the cooling medium emerges during the operation of the rocket engine from the cooling channel 20 and passes into an outlet line, of no further relevance here. In an alternative it is provided that the inlet distributor 24 is arranged at the second end, the lower end in FIG. 1, of the thrust chamber 12, so that the cooling medium flows in the opposite direction. Components arranged in the cooling channel 20 are then oriented correspondingly oppositely. Furthermore, it is conceivable that the cooling channel, seen axially, is situated only in the region of the combustion chamber 14 or only in the region of the nozzle 16. In a further alternative, in which the cooling channel is situated only in the region of the combustion chamber, the inlet distributor 24 is arranged at the interface between the combustion chamber 14 and the nozzle 16. In this alternative, too, the cooling medium flows in the opposite direction, i.e., from the bottom upwards in the representation from FIG. 1, and the components arranged in the cooling channel 20 are oriented oppositely as in the aforementioned alternative.

[0026] In the cooling channel 20 there are arranged a plurality of bridge elements formed as bridge webs 30, 32, 34, 36, 38, which each traverse the cooling channel 20 in the radial direction with respect to the chamber longitudinal axis A (cf. FIG. 2). Bridge webs which correspond in their features bear the same reference symbols here. Each of the bridge webs 30, 32, 34, 36, 38 is in direct contact with the casing wall pieces 21, 23 and connects these wall pieces. The two casing wall pieces 21, 23 and the bridge webs 30, 32, 34, 36, 38 are produced in one piece continuously without joints (“in one casting”) by printing. The bridge webs 30, 32, 34 and 36 are arranged in the region of the combustion chamber 14 and the bridge web 38 is arranged in the region of the widening of the nozzle 16. If the cooling channel 20 is situated only in the region of the combustion chamber 14 in the case of the alternatives, the bridge webs 38 are absent.

[0027] All the bridge webs 30, 32, 34, 36, 38 are of greater length than width when viewed in a sectional area A-A oriented along the casing wall pieces (cf. FIG. 1). In the web longitudinal direction, they therefore have a greater dimension than in the web transverse direction. To give a numerical example, the bridge webs 30-38 in the web longitudinal direction may be at most 10 cm, or at most 8 cm, or at most 6 cm, or at most 4 cm long. For example, the dimension of at least a partial number of the bridge webs 30-38 in the web longitudinal direction is at most 3 cm, or at most 2 cm, or at most 1 cm. In the web transverse direction the bridge webs 30-38 are, for example, at most 3 cm, or at most 2 cm, or at most 1 cm thick. For example, at least a partial number of the bridge webs 30-38 have a thickness in the web transverse direction between about 1 mm and about 5 mm. The ratio of the length in the web longitudinal direction to thickness in the web transverse direction is, at least in a partial number of the bridge webs 30-38, for example, not less than 1.5:1, or not less than 2:1, or not less than 3:1, or not less than 4:1. The above numerical data applies not only, but in particular also, to engines with a combustion chamber diameter of at most about 1 m.

[0028] As shown, by way of example, in the partial axial longitudinal section from FIG. 2, the bridge webs 30-38 are shorter in the web longitudinal direction at their, with respect to the chamber longitudinal axis A, radially outer sides bordering on the casing wall piece 21 than at their radially inner sides bordering on the casing wall piece 23. In this respect, the length of a bridge element or bridge web in this context refers to its maximum extent in its web longitudinal direction. The bridge webs 30-38 have, viewed in the axial longitudinal section through the chamber longitudinal axis A, a trapezium-shaped cross-section, with the parallel sides of the trapezium running along the sectional area between the casing wall pieces 21, 23 and the bridge webs 30-38 and the height of the trapezium corresponding to the distance between the casing wall pieces 21, 23. Herein, trapezium-shaped means shaped like a true trapezium having two essentially parallel and two essentially nonparallel sides/edges (see FIG. 2).

[0029] Edges of the bridge webs 30-38 arranged, viewed in the axial longitudinal section, upstream with respect to the flow direction S, run perpendicularly to the surfaces of the casing wall pieces 21, 23 bordering on the cooling channel 20. Viewed in the same section, edges of the bridge webs 30-38 arranged downstream with respect to the flow direction S intersect surfaces of the casing wall pieces 21, 23, bordering the cooling channel 20, at an angle a which is maximally 30 degrees. In alternatives, the angle is maximally 25 degrees or maximally 20 degrees. Furthermore, it is conceivable that the angle is greater than 30 degrees, for example is up to 35 degrees. Alternatively, edges of the bridge webs 30-38 arranged, viewed in the axial longitudinal section, downstream with respect to the flow direction S, run perpendicularly to the surfaces of the casing wall pieces 21, 23 bordering on the cooling channel 20. It is also conceivable that edges of the bridge webs 30-38 arranged upstream with respect to the flow direction S, when viewed in the same axial longitudinal section, intersect surfaces of the casing wall pieces 21, 23, bordering the cooling channel 20, at an angle which is maximally 30 degrees.

[0030] Each of the bridge webs 30, 32, 34, 36, 38 has in the sectional area A-A a drop-shaped profile with a gently curved first end and a second end which is more sharply curved than the first end. The bridge webs 30, 32, 34, 36 are oriented in such a way that their first ends point upstream and their second ends point downstream, and around which flows cooling medium at all their surface portions not in contact with the casing wall pieces 21, 23. Both in the circumferential direction of the thrust chamber 12 and in the longitudinal direction parallel to the chamber longitudinal axis A, each of the bridge webs is arranged spaced from the other bridge webs, so that there is no contact between the bridge webs 30, 32, 34, 36, 38 (see FIGS. 3 and 4). Moreover, the bridge webs 30, 32, 34, 36 and 38 are arranged spaced from the inlet distributor 24.

[0031] FIGS. 2 and 3 show, by way of example, that the bridge webs 34 are larger, in particular longer and wider, than the bridge webs 32 and smaller, in particular shorter and narrower, than the bridge webs 30. Accordingly, a smaller number of bridge webs 30 are arranged beside one another in the circumferential direction in a particular region/at a particular height along the axis A than bridge webs 32. As a result, for example in the region of the bridge webs 30, a lower flow velocity is achieved than in the region of the bridge webs 32. Thus, in the region of the bridge webs 32, a greater quantity of heat can pass to the cooling medium than in the region of the bridge webs 30. This applies analogously to the bridge webs 34 and 32.

[0032] While the bridge webs 30 and 32 in the sectional area oriented along the casing wall pieces 21, 23 are aligned parallel to one another in such a way that their web longitudinal directions (in FIG. 3 from the top towards the bottom) run parallel to one another and are oriented parallel to the chamber longitudinal axis, the bridge webs 34, although they are aligned parallel to one another, are however oriented obliquely to the bridge webs 30 and 32 and obliquely to the chamber longitudinal axis. In the view from FIG. 3, therefore, the web longitudinal direction of each of the bridge webs 34 intersects the web longitudinal direction of the bridge webs 30, 32. As a result, the flow can be deflected effectively in the circumferential direction.

[0033] The bridge webs 36 and 38 are formed in the same way as the bridge webs 30, but may optionally have the features of the bridge webs 32 or 34. Moreover, in an alternative rocket engine, any desired number of further bridge webs may be arranged between the bridge webs 30, 32, 34, 36 and/or 38 which have the features of the bridge webs 30, 32, 34, 36 or 38.

[0034] In a further alternative rocket engine (not shown in the figures), the gap between the casing wall pieces 21, 23 is divided by partition walls, extending radially and longitudinally relative to the chamber longitudinal axis A, into a plurality of cooling channels, for example into three, four or five cooling channels. In this alternative the cooling channels each have the same angular width, i.e. width in the circumferential direction with respect to the axis A.

[0035] Overall, the rocket engine described here is distinguished by a more efficient cooling of the thrust chamber. Owing to the configuration described, the flow of the cooling medium can be locally and, as a whole, precisely set, and thus the transmission of the waste gas heat improved. In particular, by means of the shaping, arrangement and number of the bridge elements/webs over the circumference and the length of the cooling channel, as well as via the relative distance between the casing wall pieces, the flow of the cooling medium can be controlled according to the wishes of the developer. This allows the heat transfer to be controlled. If the rocket engine is manufactured additively, i.e., by means of 3D printing, it is distinguished additionally by a simple and cost-effective production.

[0036] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.