GB2244120A

GB2244120A - Solid propellant rocket engine

Info

Publication number: GB2244120A
Application number: GB9110732A
Authority: GB
Inventors: Rainer Schoeffl
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1990-05-19
Filing date: 1991-05-17
Publication date: 1991-11-20
Also published as: DE4016220A1; FR2662212A1; GB9110732D0

Abstract

A solid propellant rocket engine container has two or more parts to facilitate the incorporation of propellant charge therein, the parts being held together and strengthened by means of directed wrappings thereon of fibres in a synthetic resin matrix. The container may be in two pants which engage coaxially along a circular line extending around the cylindrical body section, and the fibres in the connection region may lie predominantly parallel to the container axis. The base region of the container around the nozzle(s) may also be reinforced.

Description

Solid propellant rocket enaine -111 Ill This invention relates to a rocket

engine incorporating a solid propellant-containing container 5 having at least one nozzle.

Such a rocket engine is described in principle in H. Dathan, "Waf fenlehre fuer die Bundeswehr", second edition, Bonn, pg 154 ff. Modern solid propellants for such an engine are e.g. so-called two- or double-base fuels or composite fuels. The introduction of a propellent charge formed from such propellants into the container has associated difficulties and usually means that the container must be opened, e.g. by way of a removable base. The connection of the base to the container by a thread or by way of snap rings involves, however, considerable manufacturing expense and, from the point of view of strength, often is a source of weakness of the rocket engine.

A method is known from DE-A-2 200 196 for directionally reinforcing a cylinder wall of a rocket engine in the axial direction with threads or fibres. The fixing of the fibre ends is, however, a source of considerable expense.

According to the present invention, there is provided a rocket engine incorporating a solid propellant-containing container having at least one nozzle, which container has two or more parts and the container parts are held together by an armouring of fibres in a synthetic resin matrix provided on the container.

It is particularly preferred to have a monofilament winding, especially a wrapping of the container on the container on the outside with monofilaments in a synthetic resin matrix, such that as many fibres as possible contribute to a tensioned connection between the container parts. Winding techniques as well as types of fibres to use (aramide, carbon, glass) and the matrix, into which the fibres have to be bound, may be of currently known types. Because of the disposition of propellants in the container, resins which harden at ambient temperature or at slightly elevated temperature are preferred as matrix.

Preferably, the container is in two parts, has a cylindrical body section and has both container parts engaging coaxially. It is then preferred that the container parts engage along a circular line extending around the cylindrical body section of the container with the fibres preferably extending in the body section where the two parts are connected so as to lie predominantly parallel to the cylinder axis.

A firm connection of the housing parts with each other is to be achieved by means of the fibre armouring.

Without special further expense, however, other locations (e.g. in the base around the nozzles) can also be reinforced by the fibres, so that the whole container can be designed to be relatively light from the start.

Because of the desirability of providing an external fibre armouring, the container itself can also be constructed completely or partially of non-metallic materials, for example fibre-reinforced plastics, such as epoxy resin with carbon short fibres.

For a better understanding of the invention and, to show how the same can be carried into effect, reference will now be made by way of example only to the accompanying drawings, wherein:

Figure 1 shows a Section A-A in Figure 2 through a 1 v r solid propellant rocket engine, Figure 2 shows a Section B-B through a solid propellant rocket engine according to Figure 1; and Figure 3 shows a plan view of a rocket engine in direction C according to Figure 1.

A solid propellant rocket engine 1 according to Figure 1 includes a container consisting of two parts 2,3. The two container parts 2,3 are connected at a line 4 which lies in a casing region 5 and is here a circle. Inserted in the connecting region there is a sealing ring 6. The container part 3 includes four thickened parts 7, which accommodate nozzles 8 with linings 9.

in the centre of the container part 3 there is a pyrotechnic charge 10, by means of which a propellent charge 11 can be ignited. The charge 10 is held in place by a glued-on cover 12 and can be initiated by a primer capsule 13. The solid propellent charge 11 is itself glued into the container part 2. An insulating layer 14 can be identified between the solid propellent charge 11 and the housing part 2.

The connection of the two container parts 2,3 takes place externally around the container 1 essentially by means of a carbon fibre winding 15 in a resin matrix. The fibre armouring gives the container 1 a high strength. In the region of the junction plane between the container parts, the largest amount of fibre possible should be present and aligned perpendicularly thereto. The individual fibres of the fibre winding 15 extend therefore in the casing region 5 of the container predominantly in an axis-parallel manner. The container parts 2,3 are initially glued in the connecting region 4, to simplify the wrapping of the container 1. This i 1 connection need not, however, be of high quality or expensive, because the strength of the container 1 is fixed by the fibre armouring 15. The wall thickness of the container parts 2,3, is lowered relative to the traditional design. The container parts 2,3 themselves consist of GRP or CRP (with short fibres), thereby leading to a relatively lightweight rocket engine.

The section B-B through the rocket engine as shown in Figure 1 which is to be seen in Figure 2 shows that the propellant charge 11 has, in the axial region a starshaped surface 16, because the propellent charge 11 is designed as a so-called internal burner, which makes possible a constant gas quantity per time unit for a longer period.

In Figure 3 the fibre course 15 in the base region 3 of the cylindrical container 1 is represented in a simplified manner by thick fibre strands 17. In the base region these fibres extend substantially radially; they are guided around the thickened parts 7 which have the nozzles 8.

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Claims

1. A rocket engine incorporating a solid propellant-containing container having at least one nozzle, which container has two or more parts and the container parts are held together by an armouring of fibres in a synthetic resin matrix provided on the container.

2. A rocket engine according to claim 1, wherein the container is wrapped on the outside with monofilaments in a hardened synthetic resin matrix.

3. A rocket engine according to claim 1 or 2, wherein the container is in two parts, has a cylindrical body section and has both container parts engaging coaxially.

4. A rocket engine according to claim 3, wherein the container parts engage along a circular line extending around the cylindrical body section of the container.

5. A rocket engine according to claim 3 or 4, wherein the fibres extend in the body section where the two parts are connected so as to lie predominantly parallel to the cylinder axis.

6. A rocket engine according to any one of claims 1 to 5, characterised in that the synthetic resin matrix is formed from a resin, which is able to harden at ambient temperature or at slightly elevated temperature.

7. A rocket engine according to any one of claims 1 to 6, wherein the container has base regions which are also reinforced.

8. A rocket engine according to one of claims 1 7, wherein the container parts themselves are made completely or partially of fibre-reinforced synthetic plastics material.

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9. A rocket engine according to claim 8, wherein the container parts are formed of epoxy resin containing carbon short fibres.

10. A rocket engine substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

Published 1991 at 71be Patent Office, Concept House. Cardiff Road, Newport. Gwent NP9 1RH. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile Point Cwmfelinfach, Cross Keys, NewporL NP1 7HZ. Printed by Multiplex techniques ltd, St Mary Cray, Kent.