FR2666143A1 - DEVICE FOR EXHAUSTING GASES FOR VERTICAL LAUNCH MODULE OF MISSILES. - Google Patents

Abstract

Gas evacuation device for vertical missile launch module. It is characterized in that it is constituted by several discharge conduits (9) distinct from one another and each communicating with a plenum (7), at least part of said conduits being of revolution about a vertical axis. Application to vertical launch modules from a surface building.

Description

GAS EXHAUST DEVICE FOR LAUNCH MODULE

VERTICAL OF MISSILES

  The present invention relates to a gas evacuation device for vertical launch module which comprises cells regularly distributed around a gas evacuation chamber and in each of which is disposed a missile, and more specifically for a vertical launch module from missiles from

of a surface building.

  The vertical launch modules equipping a building

  The surface modules are generally recessed below the deck of the building. In order to allow them to be recessed under the deck, the modules each include a device for evacuating the propulsion gases produced during a normal fire from a missile or inadvertent ignition. which evacuates the propulsion gases through the upper end

or from the top of the module.

  Various architectures of launch modules

vertical have been proposed.

  In one of the possible architectures, each

  vole is defined by a missile launcher container, the evacuation of gases being provided by means provided

in each container.

  Another architecture, more widespread, includes a plenum or plenum, in which the propulsion gases are collected, and a chimney

  unique top evacuation of the propulsion gases.

  To do this, and in order to reduce as much as possible the area occupied on the bridge, for reasons that are obvious, the plenum was formed at the base of the cells containing the missiles and the single chimney in rectangular form between two rows of columns. The rectangular chimney is metallic and has a section of

  passage for the evacuated gases relatively narrow.

  It is necessary, given the pressure of the gases, to provide relatively thick walls and therefore a very large weight of material, which constitutes a

serious inconvenience.

  Another disadvantage is that the metal can be

corroded in the long term by gases.

  In addition, the rectangular shape adapts poorly, not to say almost impossible, to an embodiment of the chimney from a composite material, filament winding in particular, which could have been a solution to the reduction of

  mass, because of the lightness of composite materials.

  The present invention aims to overcome the aforementioned drawbacks and its object is a device for evacuation of propulsion gas, as large as the central rectangular chimney, but a considerably reduced weight while having excellent resistance to gas propulsion both from the point of view of

the pressure as corrosion.

  The present invention relates to a gas evacuation device of the type connected to a plenum and which is characterized in that the evacuation device is constituted by several separate evacuation conduits from each other and each communicating with said plenum at least some of said conduits being of

  revolution around a vertical axis.

  An advantage of the present invention lies in the fact that the gas evacuation device can be considerably lightened, while having a total passage cross section for the propulsion gases at least equal to that presented by a single chimney. In addition, the manufacture and installation of separate conduits are easier to achieve: finally, it now becomes possible to use materials other than metal, such as highly resistant composite materials and which are not corroded by the gas

propulsion.

  Other advantages and characteristics

  1 is a perspective view of a vertical launch module equipped with a propulsion gas evacuation device. according to one embodiment of the invention; Figures 2a and 2b are schematic representations of the gas passage sections in a rectangular chimney and in separate ducts, respectively; FIG. 3 is a curve representing the instantaneous pressure in the evacuation device as a function of the flow rate in the ducts; FIG. 4 is a diagrammatic representation of another embodiment of a

device according to the invention.

  The vertical launch module, shown in FIG. 1, comprises a structure 1 in which missile receiving cells 2, not shown, are formed, the cells 2 opening into an upper plate 3 through upper openings 4 and in a

  lower plate 5 by passages 6.

  The passages 6 communicate with a plenum or plenum 7 which occupies most of the base 8 of the structure 1. The device for evacuating the missile propulsion gases is constituted in the example shown in FIG.

  FIG. 1 by four separate conduits 9, preferably

  cylindrical shape, which are arranged between the upper and lower plates 3 and 5, on the one hand, and between the passages 6, on the other hand, so as to

  occupy the volume of the module delimited by the cells.

  Each duct 9 communicates with the plenum 7 and opens out into the atmosphere through its upper end 10, either directly at the level of the upper plate 7 or via a collecting chamber. The means for closing and isolating the device evacuation of the propulsion gases are not shown and can

be of any suitable type.

  In Figure 2a is shown schematically

  the section S 'of a single chimney 11 of evacuation

  The chimney 11 due to the thickness e of the walls 12 offers only a passage section S which is substantially less than or equal to half of the section SI which is the available section.

  between the cells of the vertical launch module.

  As shown diagrammatically in FIG. 2b, using said available section, at least four rolls of diameter equal to the width of the stack 11 can be provided, which already offers a total passage section for the upper propulsion gases. In the case of an eight-slot vertical launching module (FIG. 1), the evacuation ducts or cylinders 9 can be aligned with the openings 4 of the cells, which limits the number of ducts.

  evacuation to four, imposed by the available section.

  In the case of FIG. 4, the evacuation ducts 13 are three in number but arranged in staggered rows with respect to the cells of the module, but

  each with a larger passage section.

  Each exhaust duct 9 or 13 can be made independently of a composite material that is both light and resistant, using a technique already proven in the space industry. For example, they can be made from a composite filament winding. can also achieve metal because the form of revolution of the ducts reduces the required thicknesses compared to those of a rectangular shape, the overall mass of the four metal exhaust ducts being two to three times lesser

  only with a rectangular geometry.

  Simulations carried out with the device according to the invention made it possible to verify that the flow rate of the

  Propulsion gases contained in Plenum 7 are distributed

  knows equitably between the exhaust ducts and to have at the entrance of each duct a gas pressure

substantially the same.

  This is explained in the following way in

reference to Figure 3.

  The general gas flow regime requires, in order to pass from a subsonic flow to a transonic then supersonic flow, a very strong rise in

  instantaneous pressure at the entrance of an evacuation

  This relationship is materialized by curve 14, the hatched area representing the pressure prevailing in

6 2666143

  the plenum for a transonic flow in the

exhaust ducts.

  In zone D 1 (subsonic flow), the flow rate per unit area is relatively low, and a flow increase corresponds to a relatively small increase in pressure above atmospheric pressure Pa. evacuate through one or more of the exhaust ducts. When the flow tends to increase in a conduit 1 i but located in the zone D 2 (transonic flow),

  the increase in flow is authorized by an increase

  the pressure available at the inlet of said duct, which pressure is less than or equal to the pressure of the

gas in the plenum.

  On the other hand, when the surface flow rate in one of the ducts tends to enter the zone D 3 (supersonic flow), then the pressure necessary to enter the duct is not sufficient and it is consequently deviated towards the adjacent duct. what

balance the flows.

  Therefore according to the invention, depending on the dimensions of the plenum and the available section between the cells, we choose passage sections for the evacuation ducts that are such that we have a subsonic flow or at the limit transonic on

all the ducts.

Claims (4)

  1 Gas evacuation device for vertical launch module with multiple cells (2) for missiles evenly distributed around the evacuation device   which is connected to a plenum (7) or room of tranquility   the gas discharge, characterized in that the evacuation device is constituted by several separate evacuation ducts (9) and each communicating with said plenum, at least a part of said   conduits being of revolution about a vertical axis.   2 Device according to claim 1, characterized in that each of the ducts (9) is cylindrical. 3 Device according to claim 2, characterized in that the sections of the cylindrical ducts are equal.   4 Device according to one of claims 1 to 3,   characterized in that the conduits are metallic.   Device according to one of Claims 1 to 3,   characterized in that the ducts are made from   windings of a composite material.   Device according to claim 5, characterized   in that the windings are filamentary.