Abstract:
A submersible apparatus is configured to eject air and/or water in desired predetermined patterns to simulate particular types of ordnance to facilitate safe and effective splash testing of ship radar systems. The apparatus includes a frame, one or more adjustable buoyancy bodies, a source of fluid such as an air compressor or a water pump, and a plurality of nozzles through which the fluid is ejected to create the desired splash. Fluid can be supplied to the buoyancy bodies to adjust the level of the apparatus in the water as necessary to simulate a particular type of ordnance. Additionally, the nozzles can be individually adjustable to facilitate ordnance simulation. A control system is provided to enable remote and/or preprogrammed control of the apparatus. A wireless or hard wired link can be provided to allow a remote user to control the apparatus in real time.

Description:
FIELD OF THE DISCLOSURE 
     The invention relates generally to the field of ship systems testing, and more particularly to a system for simulating ordnance splashes for testing of ship combat systems. 
     BACKGROUND OF THE DISCLOSURE 
     One of the critical items verified during US Navy testing at sea is the ability of the vessel sensors to maintain track continuity in the presence of splashes generated by Naval Gun Fire, within the vicinity of the target(s). Multiple aspects of Naval testing, such as Layered Defense Exercises, Track Correlation, Optical Sight/Video Tracker evaluation, and Electronic Warfare require evaluating performance in a splash environment. To accomplish this task, various types of live ordinances may be used as a function of the type of mission and sensors being evaluated. Each type of round generates a splash whose characteristics in terms of size, shape, and height are unique to that round. 
     The use of live rounds to evaluate sensor performance is a very expensive approach due to the associated hourly cost of Navy ship/Crew at sea, as well as the cost of ordnance and safety vessels to support such effort. 
     It would thus be desirable to develop a system that enables ordnance splash testing to be conducted for US and FMS Navy vessels. The desired system should enable splash testing to be performed safely at sea or near port, with minimal impact on surrounding people and vessels. 
     SUMMARY OF THE DISCLOSURE 
     The disclosed device provides an effective simulation of ordnance splash patterns without the need for firing live ordnance. The device includes a submersible apparatus having the ability to eject air and/or water in desired predetermined patterns to simulate particular types of ordnance. The device allows splash testing to be performed at shore facilities or in port areas, and at reduced cost, since operation of ships at sea is not required. Performing splash testing with the disclosed device also reduces the test load during CSSQT, which allows for enhanced scheduling of other essential tests. The device is applicable to testing performed on any Navy ship Class. 
     A splash simulation device is disclosed, comprising a submersible frame and a plurality of buoyancy bodies mounted to the submersible frame. The plurality of buoyancy bodies may be capable of maintaining the submersible frame at a desired depth in a body of water. A plurality of fluid flow nozzles are mounted to the frame. The device also includes a fluid source in fluid communication with at least a portion of the plurality of fluid flow nozzles. When the submersible frame is placed in the body of water, at least a portion of the fluid flow nozzles are oriented toward a surface of the body of water. 
     A submersible device for simulating an ordnance splash is disclosed. The device comprises a frame and a plurality of buoyancy bodies mounted to the frame. The plurality of buoyancy bodies may be capable of providing a buoyancy force to said frame when said frame and bodies are placed in a body of water. The device further comprises a plurality of fluid flow nozzles mounted to the frame, and a fluid source connected to the plurality of fluid flow nozzles. When the submersible frame is placed in said body of water, at least a portion of the plurality of fluid flow nozzles are oriented toward a surface of the body of water to enable creation of a splash at the water surface level when fluid is supplied to the plurality of fluid flow nozzles. 
     A submersible splash simulation device is disclosed, comprising a frame and a plurality of buoyancy bodies associated with the frame. The plurality of buoyancy bodies are capable of maintaining the frame at a desired level when the frame is placed in a body of water. A plurality of fluid flow nozzles are associated with the frame, and a fluid source is connected to the plurality of fluid flow nozzles for moving fluid through the nozzles. When the submersible frame is placed in said body of water, at least a portion of the plurality of fluid flow nozzles are positioned to create a splash at the water surface level when fluid is moved through the nozzles. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The details of the invention, both as to its structure and operation, may be obtained by a review of the accompanying drawings, in which like reference numerals refer to like parts, and in which: 
         FIG. 1  is a plan view of the disclosed submersible splash simulation device; and 
         FIG. 2  is a side view of the submersible splash simulation device of  FIG. 1   
         FIG. 3  illustrates the control system for use with the device of  FIG. 1 ; 
         FIG. 4  shows an exemplary nozzle control arrangement for use with the device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     In the accompanying drawings, like items are indicated by like reference numerals. This description of the preferred embodiments is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description of this invention. In the description, relative terms such as “lower,” “upper,” “horizontal,” “vertical,”, “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description and do not require that the apparatus be constructed or operated in a particular orientation. Terms concerning attachments, coupling and the like, such as “connected” and “interconnected,” refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. 
     The disclosed submersible splash simulation device provides a simple and inexpensive way to simulate ordnance splashes to facilitate testing of ship sensors such as radar systems. The disclosed device is capable of generating splashes for the purpose of simulating splashes created by rounds from gun fire (e.g., MK45 or other gun type). The device may include multiple air compressor units and/or pumps to generate the desired fluid ejection force, as well as a multiplicity of firing nozzles. The device can be programmable to fire selected nozzles, where each selection of specific nozzles and discharge pressures will simulate a type of ordnance round at different levels of intensity. A remote control unit can be used to program the device and to fire the desired pattern upon request. 
     In one embodiment, the discharge may consist of water driven by compressed air. In another embodiment, the water may be driven by centrifugal or positive displacement pumps. In a further embodiment, a combination of water and air may be discharged simultaneously from selected nozzles. 
     Referring now to  FIGS. 1 and 2 , the submersible device  1  may comprise a stabilizing truss structure  2  on which a plurality of adjustable buoyancy bodies  4  are mounted. Elongated members  6  run along the top of the truss structure  2  and include a plurality of nozzles  8  through which air, water or a combination thereof can be expelled. In the illustrated embodiment, one elongated member  6  runs the length “L” of the device  1 , while two other members  6  are positioned at acute angles thereto. Other arrangements, however, can be used as desired to provide a desired strength and stiffness to the device  1 , and also to position the nozzles  8  in a desired pattern. 
     One or more of the nozzles  8  may be fixed in position, or they may be position adjustable. In addition, the individual orifice size of each of the nozzles may be fixed or adjustable to enable the system to finely control the flow rate of water and/or air expelled from the nozzles. The position and/or orifice size of the nozzles may be locally or remotely controlled. 
     A housing  10  may be positioned within the truss structure  2 . The housing  10  may enclose an air compressor  12  and water pump  14  for supplying fluid to the plurality of nozzles  8 . A retractable air vent  16  enables the intake of air to the compressor  12 , while a suction intake  17  provides a path for water to enter the water pump  14 . The air vent  16  may be retractable so that it does not contribute to radar returns during testing. 
     Discharge ports of the air compressor  12  and water pump  14  are in fluid communication with the nozzles  8  to enable air, water, or air/water combinations to be pumped through the nozzles  8  to achieve a desired splash effect. In one embodiment, the fluid is supplied to the nozzles using piping or tubing disposed within the elongated members  6 . A plurality of air compressors  12  and/or water pumps  14  can be used to provide the desired fluid flow-rates required for a particular application. As an alternative or supplement to the air compressor  12  and/or water pump  14 , a source of compressed fluid can be provided, such as compressed air or nitrogen cylinders. 
     The air compressor  12  and water pump  14  may also be in fluid communication with the adjustable buoyancy bodies  4  to enable water to be introduced and evacuated from the bodies to control the position of the device  1  with respect to the surface of the water. Compressed air may be supplied to the adjustable buoyancy bodies  4  by a combination of pipes and tubes disposed within the elongated members  6 . Alternatively, or in addition to, such piping and tubing, the elongated members  6  themselves may be used as flow paths for providing compressed air to the bodies  4 . 
     The adjustable buoyancy bodies  4  may be simple containers that will have the quantities of air and water adjusted to achieve a desired level of buoyancy. The bodies  4  may include internal baffles to reduce instability caused by internal water motion (i.e., sloshing). The device may include electronic level and pressure sensors for one or more of the bodies  4  to determine changes in buoyancy required to maintain the device&#39;s attitude as well as height in the water. 
     The device  1  may also comprise an on-board control system  18  for controlling one or more device operations. The control system  18  may control filling/evacuation of one or more of the buoyant bodies  4  to control the position of the device below the surface of the water to thereby achieve a desired splash effect. In one embodiment, the device will be up to 10 feet below the surface of the water. 
     The control system  18  may also control the ejection of air and/or water through one or more of the nozzles  8  to simulate a desired ordnance splash. To this end, the control system  18  may be remotely controlled in a “live” fashion so that an operator on an adjacent vessel or on land can command the operation of the device  1  in real time. Alternatively, the control system  18  may be programmed to configure the device  1  into one or more predetermined modes of operation that will simulate one or more ordnance splash patterns. 
     Referring to  FIG. 3 , the on-board control system  18  may include a communication link  22  to a remote control system  24  to enable remote control of the device  1  from a nearby ship or on land. The remote control system  24  may automatically or manually forward commands and modes of operation to on-board control system  18  of the device  1 . Where a wireless connection is provided, the on-board control system  18  may include one or more antennas  20  mounted on or adjacent to the truss structure  2  and/or the housing  10 . 
     A variety of wireless and hard-wired communications links  22  may be used to remotely control the device  1 . In one embodiment, communications between the device  1  and the remote control system  24  may be via VLF (Very Low Frequency) or VHF/UHF (Very High Frequency/Ultra High Frequency) modes. For VLF communications, the device  1  can include an underwater antenna  26  to receive/transmit commands from the remote control system  24 . For VHF/UHF communications, the device  1  can include a whip antenna  20  ( FIG. 2 ) protruding above the water to receive/transmit commands from the remote control system  24 . Where a whip antenna  20  is used, the radar cross section of the antenna will be such that it is not detectable by radar. 
     Communications between the device  1  and the remote control system  24  may be one-way or two-way. The remote control system  24  may be an existing communication device aboard a US Navy ship, or it may be a transmitting device specifically designed for communicating with the device  1 . The on-board control system  18  may comprise an RF receiving device  28 , a computer (i.e., processor  30  with memory  32 ), and electro-mechanical apparatus  34 . The electro-mechanical apparatus  34  may comprise a device that receives control signals from the computer or processor and triggers a desired mechanical function (e.g., turn on/off the air compressor  12  or water pump  14 , actuate the nozzles  8 , etc.) using a relay, solenoid, or the like. 
     As previously noted, the control system  18  may control the splashes generated by the system  1 . Referring to  FIG. 4 , each nozzle  8  may be controlled by a valve  36  and a variable orifice  38  to regulate pressure. The valves  36  may be operated by either pneumatic or electric servos. The exact combinations of water and air nozzles to be used for each type of splash may be fine tuned experimentally after initial settings have been determined. This fine tuning may be completed by a manual select mode. Once the combinations are known, the parameters may be used to populate a look up table associated with the processor  30 . As additional splash forms are identified, the new splash profiles can be added to the look up table. 
     As can be seen in  FIG. 2 , certain of the discharge nozzles  8  are positioned at a level higher than the buoyant bodies  4  to ensure that only the simulated splashes, and not the structure of the device  1 , contribute to radar returns of the unit under test. Depending on the type of splash required to simulate a certain type of ordnance, the device  1  may be used in a manner that requires the discharge nozzles  8  to be placed very close to the surface. In this type of use, gentle wave action may expose the buoyant bodies  4  above the water if they are not lower than the nozzles  8 . Allowing the buoyant bodies to extend above the water would undesirably change the RF return of the device. 
     The position of the device in the water will be controlled by anchorage. In alternative embodiments, the device  1  may be position stabilized by use of a GPS navigation system in conjunction with water jets powered by the same pumping system (water pump  14  and/or air compressor  12 ) that generates splashes, but directed to horizontally aimed nozzles  40  ( FIG. 2 ) capable of providing lateral thrust to move the device in the water. 
     Portions of the device  1  that will be subjected to the body of water may be constructed of 5000 series corrosion resistant aluminum. Internal piping/tubing may be constructed of stainless steel with fittings of stainless steel or aluminum. The nozzles  8  may be aluminum. All material selections can be made to avoid galvanic cells at interfaces between material types. Sacrificial anodes may be used to reduce corrosive effects of salt water immersion when performing splash testing in seawater or brackish water. 
     As previously noted, the system  1  can be used to simulate splashes generated by most US and foreign Naval guns. Examples of such US guns include: MK 45-38, 54 and 62 Caliber, MK 38—25 mm, and Phalanx Weapon System—20 mm. Examples of such foreign Naval guns include Bofors—57 mm (Swedish), OTO—Malera 127 mm/54 (5″) (Italian), 40 mm/70 OTO-Breda (Italian), and 76 mm/62 (3″) (Italian). Air, water or air/water discharges from the system  1  can be used to simulate splashes generated by each of these rounds. 
     As will be appreciated, the disclosed system provides the ability to conduct thorough testing of ship sensors systems while the ship is in port at reduced cost. Performing the same testing during CSSQT is substantially more costly due to the hourly rate for the ship/crew and the required support vessels presently needed for safety. Conducting this portion of testing outside CSSQT will reduce the required time to perform surface events such as Layered Defense Exercises, Track Correlation, Optical Sight/Video Tracker evaluation, and Electronic Warfare performance in the presence of splashes generated by Naval Gun rounds. In addition, the disclosed system will reduce the test load during CSSQT allows for enhanced scheduling of other essential tests. 
     Although the invention has been described in terms of exemplary embodiments, it is not limited thereto. Rather, the appended claims should be construed broadly, to include other variants and embodiments of the invention, which may be made by those skilled in the art without departing from the scope and range of equivalents of the invention.