1. Technical Field
The embodiments herein generally relate to weapons systems, and, more particularly, to equipment used for protection against the exhaust gases of missile launching systems.
2. Description of the Related Art
A vertical launching system (VLS) consists of a number of cells for holding and firing missiles on surface ships and submarines used by many navies around the world. Typically, each cell can hold a number of different types of missiles, enabling the ship flexibility to load an appropriate set for a given mission and to enable replacement of earlier missiles with upgrades without expensive rework. When the command is given, the missile flies straight up long enough to clear the cell and the ship, and then turns on course. The most popular VLS system in the world is the MK 41, being used by eleven navies around the world. The United States Navy will employ the MK 57 VLS on the U.S.S. Zumwalt class destroyers.
Both MK 41 and MK 57 VLS missile launchers primarily are configured as a plenum and uptake type gas management system. A plenum is a pressurized chamber holding fluids, and the uptake refers to the general upwards/vertical venting of pressurized gas from the plenum. These systems manage gases during a normal missile launch and also during retrained firing. However, a typical plenum and uptake approach results in substantial structural wear caused by normal missile launches, which decreases the ability to withstand a restrained firing, thus, limiting the number of missiles that can be launched prior to gas management system refurbishment.
The MK 41 and MK 57 VLS gas management system plenums protect their plenum floors with ablative material. Additional protection is provided underneath the rocket motor by using a bi-layer ablative material stack. The material on top of the stack is exposed to the rocket motor plume during normal missile fly outs, and the material on the bottom of the stack is exposed only during a missile restrained firing. However, the material is generally inadequate to prevent burn-through when exposed to plume jetting and long burn times because the ablative material, which tends to be expensive, typically do not have sufficient mechanical strength to resist the forces produced by the plume impingement.
The Mk 41 VLS gas management system also uses an aft closure, grid, and sill. The aft closure is a square multi-material, multilayer plate that has diagonal scores that allow it to “blow open” during a rocket motor firing. The sill keeps the aft closure from opening too far and the grid prevents the adjacent aft closures from opening in the opposite direction. However, this type of system requires a substantial number of components, the aft closure layup uses many different materials and a very process-intensive assembly, and the sill and grid are relatively difficult to manufacture and assemble. Moreover, this system is not readily adaptable for use on a general plenum box assemblies because it requires more space above the top of the plenum and more intrusion into the inside of the plenum.
Therefore, it is desirable to develop an improved gas management system that utilizes the plenum and uptake configuration and is readily adaptable in current weapon systems at reduced cost and complexity. In view of the foregoing, an embodiment herein provides a system for directing a flow of gas, including a launching mechanism, a plenum, a layer of meltable material, and an open-ended uptake component. In various exemplary embodiments, the launching mechanism is adapted to expel rocket exhaust gas.
In various exemplary embodiments, the plenum includes an upper portion having at least one fire resistant breachable plug. The upper portion is adjacent to the launching mechanism. The layer of meltable material is disposed on the upper portion. The heat generated by the gas melts the layer of meltable material. The open-ended uptake component operatively connects to the plenum. The plug moves onto a lower portion of the plenum due to force generated by the gas onto the plug, and the gas flows through the plenum and the uptake component to vent said gas in a controlled manner.
These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The embodiments herein provide a gas management system that utilizes the plenum and uptake configuration to provide protection from the deleterious effects of a rocket plume. Referring now to the drawings, and more particularly to
In
As illustrated, the gas management system 10a includes a plenum 15 having an upper portion 17 with a plurality of breachable (i.e., movable) plugs 55a, 55b; a lower portion 16; and a chamber 18 separating the upper portion 17 from the lower portion 16. The system 10a also includes an uptake component 20 operatively connected to the plenum 15. In an optional embodiment, at least one gas blast protection component 30 (not shown in
As shown in
The layer of fire resistant material 65 may be configured to be substantially aligned with the plugs 55a, 55b. Due to the fire resistant qualities of the plugs 55a, 55b, the floor 16 of the plenum 15 is protected from the deleterious effects of the gas 45 without the need of a gas blast protector 30. Additionally, once the plug 55a hits the lower portion 16 of the plenum 15, the plug 55a provides the same gas diversion quality as the raised bumps 32 of a gas blast protector 30. However, should additional protection of the floor 16 of the plenum 15 be desired, then the embodiments herein may incorporate a gas blast protector 30 in the plenum 15. The uptake component 20 comprises a first open end 21 connected to the plenum 15 and a second open end 25 to permit controlled venting of the gas 50.
The plugs 55a, 55b move in substantially one direction only (i.e., generally in the direction from the upper portion 17 to the lower portion 16 of the plenum 15). The discharged plug 55a caused by the hot missile exhaust gas 45 creates an opening 19 in the upper portion 17 of the plenum 15 located directly underneath the exhausting rocket motor (e.g., rocket/missile 43 of
Accordingly, since the non-exhausting rocket motors do not direct hot gas 50 onto plug 55b, then the plug 55b remains in place in the upper portion 17 of the plenum 15 without breaching. Therefore, only plug 55a is breached because a rocket is launched directly above this location of the upper portion 17 of the plenum 15. The gas 45 directed onto the plenum 15 first strikes the layer of meltable material 60 over the upper portion 17 of the plenum 15.
The heat capacity of the meltable material 60 is less than the temperature of the gas 45 thereby causing the material 60 to melt, which then allows the gas 45 to strike the plug 55a at a force sufficient to cause the plug 55a to dislodge from the upper portion 17 of the plenum and down towards the lower portion 16 of the plenum 15. The layer of fire resistant material 65 restrains the gas 45 from causing the breach of adjacent plug 55b and to maintain the structural integrity of the remaining areas of the upper portion 17 of the plenum 15. The meltable material 60 and the fire resistant material 65 of the plugs 55a, 55b are not restricted to particular materials and need only be dictated by the thermal environment.
The system 10a protects a launcher 35 and surrounding equipment from the effects of a restrained firing even though the launcher 35 was not necessarily designed to mitigate a restrained firing. Due to the use of the fire resistant material 65, the gas management system 10a does not wear out due to the number of missile firings occurring.
By utilizing the plugs 55a, 55b and multi-layered 60, 65 upper portion 17 of the plenum 15, the embodiments herein achieve higher mechanical strength by combining the meltable material 60 and the heat resistant material 65. This is because meltable materials are plentiful and can be selected for higher strength, whereas heat-resistant materials are more specialized and typically weaker mechanically. Furthermore, the plugs 55a, 55b are relatively easy to machine due to the materials that they constitute, which reduces manufacturing costs.
The embodiments herein also permit the redirection of the exhaust gases 45, 50 such that their detrimental effects on structural components (i.e., plenum 15) are mitigated. The embodiments herein require fewer components and fewer materials than conventional gas management systems because the system 10a utilizes a less complex configuration by requiring less room above and inside the plenum 15 (e.g., the embodiments herein do not require an additional gas blast protector 30). This is because, the system 10a does not use a grid, and since a sill is also not required, there are no required extraneous flow inhibiting items protruding into the plenum 15.
While various material descriptions are described herein, the gas management system 10a may be made from a number of materials for the structural as well as the heat resistant aspects of the design. The materials used for the system 10a can be chosen based on mechanical strength under high heating rates and long burn time, ease of machining, ease of availability, and cost.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
The invention described was made in the performance of official duties by one or more employees of the Department of the Navy, and thus, the invention herein may be manufactured, used or licensed by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.