Communications/ TDL 2
Tuesday 5th September, 1100hrs–1230hrs
A Novel Photonic Antenna for wideband wireless communications
A new photonic antenna will be presented, capable of operating in 3 separate wavelengths, up to 22 GHz.
It is a combination of a WIP (Waveguide integrated Photodetector) and a three element folded slot antenna. The antenna feed is provided through a CPW (CoPlanar Waveguide) line, that constitutes the biasing line of the photodetector at the same time.
Novel designs for band pass filters and low loss transmission lines are used to minimize propagation losses.
The high efficiency of the antenna as well as the photodetector cancel the need for microwave amplifiers or any active RF elements. Amplification can be provided, if required, in the optical domain. Measured data and simulations for various antenna/photodetector configurations will also be compared and discussed.
Total Warship Survivability Assessments.
Mr Terry Turner, Defence Science and Technology Organisation (DSTO), Australia
Stuart Cannon, DSTO, Australia
Following recent events such as the grounding of HMS Nottingham off the Australian coast the Royal Australian Navy has become concerned about its rapid assessment
methods to determine the status of a damaged ship.
In response to this, DSTO has been
developing a system to support the RAN. This includes assessing the damage resulting from current weapons threats or accidental damage. The rapid assessment system then determines the residual structural strength and stability of the damaged platform.
The environmental conditions experienced by the ship needs to be considered to determine what options are available to the commanding officer. These options may vary depending upon the mission type, degree of damage and the probable environmental loads.
This paper will outline the process currently being developed by DSTO and will include a typical damage scenario as an example.
Output Feedback and Trajectory Tracking Control of a Gantry Crane
Mr Albert Ortiz, US Navy (Naval Surface Warfare Center, Philadelphia), United States
Overhead cranes are commonly used to transport heavy loads in industries and offshore shipyards. Due to the nature of a crane’s structure, there is no direct control over the position of the payload, which makes it difficult to control, and especially difficult to reduce the swing of the payload.
The objective of this paper is to design robust, fast, and practical controllers for gantry cranes. The controllers are designed to transfer the load from point to point using the shortest time. Concurrently, the payload swing is suppressed during the transfer process and completely vanishes at the load destination.
An output feedback control design and a dynamic trajectory control design are presented independently. The output feedback control is designed to move the load from point to point within one oscillation cycle without inducing large swings. The dynamic trajectory controller is responsible for making the trolley follow a reference position trajectory with minimum payload swing.
Experiments were conducted to validate the controller performance. The implemented experimental results show excellent performance of an anti-swing control mechanism.
Fully Integrated, Automated Shipboard Oil Pollution Abatement Systems
Mr. Stephen Hopko, US Navy (Naval Surface Warfare Center, Philadelphia), United States
Oil pollution abatement (OPA) systems onboard U.S. Navy vessels have traditionally consisted of loosely integrated sub-systems that require a significant degree of training and manning to operate and maintain.
In an effort to improve reliability, maintainability, operability, and performance of shipboard OPA systems, and to ultimately reduce manning requirements, the U.S. Navy has successfully completed the design, development, and testing of a fully integrated prototype automated oil pollution abatement (AOPA) system that has been partially deployed.
The AOPA system is a “smart” system that for the first time, utilizes modern control system technology, innovative programmable logic controller (PLC) programming, and complete system integration to provide effective and efficient means to automatically monitor, manage, prioritize, execute, and coordinate simultaneous shipboard oily waste transfer and processing operations.
The AOPA system consolidates sub-system control, standardizes oily waste management in a predictable manner, and eliminates subjective decision-making made by operators, while freeing up personnel for other tasks.
Speed of electromagnetic wave: Electromagnetic wave propagation speed variations and their influence on position calculations in the hyperbolic phase-location system.
Mr Ryszard Kaminski, R&D Marine Technology Centre (CTM), Poland
Knowledge about the electromagnetic wave propagation speed in air has an essential influence on a geographical position accuracy calculated by the hyperbolic phase-location system.
The measurement results of the electromagnetic wave propagation speed variations in various conditions are presented in the paper. The measurements have been made by a standard receiver of the phase-location system and two transmitting stations, one master and one slave. Measurements show systematic electromagnetic wave propagation speed changes related to the day time and various weather conditions in seasons throughout the year.
The propagation average speed is the basis for the geographical position calculation done by the phase-location system. Measurements and tests let us calculate the average speed in the region and implement corrections to calculations.
Modal representations of transient sound pulses in deep and shallow environments, with investigations about detailed space and time correlation of propagated waves.
Dr Dominique FATTACCIOLI, DGA Naval Systems, France
Xavier Cristol/ Jean-Michel Passerieux, Thales Underwater Systems SAS, France
On modern computers, mode theory may be used as a reliable competitor to ray theory, within reasonable short computing times, for modeling propagation of transient sound in both deep and shallow sea environments, up to relatively high frequencies.
Splitting transmitted pulses into narrow sub-bands, and summing up their modal contributions of modes (each with their own amplitudes, group and phase velocities) give way to simultaneous simulations of signals on different receivers. Penetration, multiple interactions inside multilayered sub-bottom, and return back to water may be considered. Space and time structure of waves may be analyzed beyond "simple" wave fronts and beyond Doppler (moving source or receiver).
Topics to be considered by this paper will be causality, aberration (departure between apparent and 'real' instant direction of arrival), and numerical strategy for minimizing rounding errors. Applications to some typical sonar configurations will be presented as illustrations.
Global Optimisation of Real-time Multi Platform Situational Awareness
Dr Hervé Fargetton, Ministry of Defence (DGA Tn), France
Alain Bambouvert, Ministry of Defence/DGA/DET/CEP, France; Félix Alvarez, DCNS, France
The French Ministry of Defence/DGA has initialised “Multi Platform Tactical Picture” research plan to evaluate, with DCNS, different architectures of communication and fusion and to define a multi platform situational awareness capability.
The communication links between platforms are supposed to be High Data Rate network and conventional Tactical Data Link. The goal is to obtain coherent and precise situational awareness on the different naval platforms so that they could conduct multi platform engagements.
A key function is global optimisation, to determine sensors tunings, data to be exchanged through the different networks and fusion algorithm adaptation so that the multi platform situational awareness responds to the operational need whatever the composition of the force and the environmental conditions (coastal areas, meteorological conditions, clutters, jamming, …).
The solutions proposed by DGA and DCNS solve the problem of global optimisation in two phases, initial conditioning and dynamic real time adaptation.
Modeling for Survivability – Compartment and Component Applications and Volume and Section Modulus Study
Ms. Sarah Juckett, Alion Science and Technology, United States
Comprehensive modeling for survivability analysis can be a time consuming and expensive process.
The value of modeling may be overshadowed by production rates of the actual ship outpacing the construction and evaluation of an accurate model for testing. Time and effort saving techniques with regards to the ship structure analysis are evaluated by applying error acceptability criteria used in Measure of Total Integrated System Survivability (MOTISS) program to the representative model construction of a notional naval auxiliary oiler.
Using an Axis Aligned Bounding Box (AABB) to represent the ship compartments, a volume and structural analysis is performed to compare the volume, loading, smeared thickness of girders, section modulus, and stresses between the actual hull form and representative AABB hull form. An error comparison is conducted at each step and applied to MOTISS’ operating theory. The time saving advantages to AABB modeling techniques are examined in the ship survivability analysis processes.
Warship Survivability Assessment from concept to service: SURVIVE and SERVIVE LITE
Mr James Schofield, Survivability Consulting Limited, United Kingdom
Since the Falklands conflict the UK has been working on the Survivability of surface warships and submarines. Comprehensive methods and policies have been developed to allow Survivability Assessment to take place from the earliest stages of a design through to in-service support.
This relies on being able to gather data, construct computer models and undertake simulation & analysis fast enough to keep track of a developing design and offer timely assistance to the Royal Navy.
Survivability advice that is only available late in the design will not be as effective. Work done to inform refit options or assess suitability for a new role or embarkation of a new munition must similarly provide timely information.
This paper will present the SURVIVE tool, used successfully in the Type 45 Destroyer and CVF Aircraft Carrier design programs as well as in support of the current Royal Navy fleet. Links to UK Susceptibility tools and descriptions of SURVIVE’s Vulnerability and Recoverability modules will illustrate the Integrated Survivability Assessments possible. Primary damage mechanisms along with secondary factors such as fire, smoke, and flooding will be described. These will be used to show how SURVIVE addresses loss of system functionality, crew, ultimate strength and stability along with the reconfigurations and repairs needed in the recoverability phase. SURVIVE’s excellent validation record against small and large scale trials and high seas firing data will be shown.
The newly available SURVIVE Lite tool for concept designers promises to revolutionise the assessment of Survivability by providing a consistent approach from the very earliest concept to the final design. Using SURVIVE Lite designers themselves can very quickly analyse and iterate their concepts. This ensures the necessary features are in place right from the beginning. The handover to Survivability Experts at a suitable stage for assessment through the design then maintains and enhances the early gains. Consistent modelling formats and assessment algorithms ensure no wasted effort and a seamless transition.
Complex of Model Experiments and Calculations as Actual Procedure for Investigation of Dynamic Towing Systems
Professor Alexander Pustoshny, Krylov SRI, Russia
Investigation of dynamic and hydrodynamic of towing systems by straight physic modeling is extremely complicated and almost impossible due to such factors as great length of system, relatively small diameter, the needs to take into consideration rigidity and unstable behavior of the rope, complicated interaction with tug ship and its wake.
That’s why combination of calculations and full scale tests becomes the conventional steps in designing of such system.
This paper will demonstrate that model experiments on proper facilities keep their position as important part of general design procedure which helps to predict and to avoid various unfavorable situations before expensive real system is manufactured.
The paper will consider the problems and tasks which should be solved for effective and safe application of systems at various operational modes, including interaction with a tug ship in rough seas. Approaches and ways to solve these problems with help of combined model experiments and computational method will be discussed.
It was shown that rational combination of experimental and computation methods open the door for effective designing.
Current AUV Developments for Mine Warfare Operations
Mr. Jean Le Gall, Thales Underwater Systems, France
Stéphane Meltzheim, ECA, France
Aware of the new trends in Mine Warfare Operations, Thales Underwater Systems has been developing AUV based sonar systems since the late 1990’s.
At present, Thales and ECA are developing 2 MCM AUVs:the first one (DTSACAM), within the frame of a French R&D 3 years contract from the Délégation Générale pour l’Armement; the second one (ASEMAR), within the frame of the French Poles of Competitiveness.
In these developments, Thales and ECA work together in a strong partnership, Thales being the System Design Authority and ECA, the expert in vehicle design.
The objectives are clearly to develop and experiment fully autonomous AUV based MCM systems.
The main components of the AUV are the embedded intelligence, the sonar payload, the navigation function and the vehicle. The AUV may communicate with the surface ship through an acoustic link. Sonar and navigation data are recorded on board the AUV.
To secure its main capabilities, the AUV takes benefit of performant functions and sub-systems.
For instance, THALES is developing a challenging on board processing that will perform automatic target recognition and determine adaptive behaviour as part of the mission management.
The system is open and modular, which means that, as future growth potentials, it may include more performant or additional functions or equipments.
This presentation will give details about the functions and performance of the AUVs and will give some preliminary results from sea trials.
Trends in Naval Optronics
Dr. Harry Schlemmer, Carl Zeiss Optronics, Germany
Old conventional submarines have two Optical Periscopes on-board. In current conventional submarines one Periscope is replaced by a non-hull-penetrating Optronics Mast System which is equipped with a HDTV and an IR camera.
For such submarines and under the necessity to offer to the Customer modern systems, Carl Zeiss Optronics has developed and manufactured
a new modern Periscope System called SERO 400 and
a new modern Optronics Mast System called OMS 100.
They are designed according to the following Customer and Yard stated requirements:
- Users require high performance optronics systems for long range reconnaissance and surveillance at day and at night.
- Logistic Personnel asks for a strongly modular structure which facilitates logistics and upgrades during the long life cycle of the systems.
- Shipyard requests for systems which meet their requirements for new developments or upgrades of submarines.
In the meantime upgrades in order to provide to the Customer higher efficient sensors and additional functionalities are in progress.
The lesson / paper presents in Part I the basic design of the Periscope System and the Optronics Mast System mentioned above and in Part II possible upgrades.
Based on the same technology, Carl Zeiss Optronics also offers Optronics Surveillance Systems for surfaces ships which will be presented in Part III.
Frigate Class F125 - An Innovative Platform for the German Navy
Dipl.-Ing. Andre Averhoff, Blohm + Voss Naval GmbH, Germany
The German Navy requires frigates which are designed for participation in international peace keeping missions.
The frigate class F125 follows the new conception of the armed forces answering challenging questions. To meet the operational requirements the reduced crew concept and the intensive use concept were developed. These are the main design drivers for platform design along with concepts such as integration of Special Forces and survivability.
Compared to the smaller sized frigate class F124 the intensive use profile entails cumulative requirements in terms of system design such as an enlarged deployment period of 24 months, enlarged operational hours of 5,000h per year in conjunction with a reduced crew of 120 sailors.
To meet those challenging requirements an expert group of of German industry, procurement office and navy is established to ensure the frigates capability and to monitor the verification process of intensive use capabilities. This is done during design, construction and acceptance tests.
Objects of investigation are functional chains, operating procedures and scheduled maintenance. Detailed requirements for availability, reliability, maintainability and supportability have to be proven.
Ensuring the platforms capability for intensive use and reduced crew requirements leads to the new Frigate Class F125, which incorporates new innovative concepts and provides the navy with the flexibility needed.
Application Of Diesel Atmospheric Pollution IMO Rules For Navy Ships: Problems And Milestones For 2011 And 2016
Dr. Dominique Mignotte, DCNS, France
Even if IMO rules concerning atmospheric pollution do not apply strictly to Navy Ships, Governments, Classification societies (e.g. ‘Clean’ Mark of BV) wants to follow the said rules. It will be difficult to find engines able to stands with IMO. The controlled areas will not make a difference between Navy and Merchant ships.
The main concern is the Nitrogen Oxyde “NOx” emissions limitation with a first step in 2011 which could be reached with difficulties and some penalties on fuel consumption. The other pollutants as Unburned Hydrocarbons, Particulates, SOx, etc, are less constraining for engines running on gazole as majority of Navy Ships. CO2 emission constraints begin to appear under definition of Index like EEDI or EEOI (which require some definition adaptations for a Navy Ship). Here we find a first challenge to decrease the NOx and not to increase CO2 emissions.
The major problem will occur in 2016 with a so drastic reduction of NOx emissions in the controlled areas (foreseen to be extended to US coasts and quite sure to the Mediterranean sea). Today, no solution of engines internal modifications exists to comply with such level. In one hand the internal modifications are so complex and costly (High Millerisation – two stages turbocharging, Exhaust Gas Recirculation as examples) and in the other hand external devices as Selective Catalyst Reactor are so costly in purchase and maintenance, that other fuel like LNG can be envisaged.
Whatever the modifications made, it will be difficult to install these new engines and or associated devices on board of Navy Ships.
Agile Test and Performance Engineering Initiatives for High Availability Systems
Mr. Edward Beck, Mission Solutions Engineering, LLC, United States
Ballistic Missile Defense (BMD) capabilities are expanding. The U.S. Navy is poised to deploy an operational sea-based missile defense system on a fleet of Aegis cruisers and destroyers. This sea-based capability will incorporate the U.S. Navy’s Open Architecture (OA) initiative which formalizes the Navy’s desire for a new combat system architecture that would be based on COTS technologies and open standards to provide an unprecedented degree of interoperability and scalability. Solution providers are challenged to create innovative approaches to meet the Open Architecture requirements while maintaining the real-time and high-performance computing requirements for Ballistic Missile Defense.
In response to the BMD and Open Architecture integration challenges, Mission Solutions Engineering (MSE), LLC, adopted an ‘Agile Test’ strategy which includes an aggressive set of performance engineering initiatives designed to characterize system performance to meet the real-time BMD and AAW weapons system requirements. This session will highlight the Integration, Test and Performance Engineering activities for MSE, LLC and the cornerstones that comprise our Agile Test efforts in support of the BMD and AAW capabilities of the Aegis Weapons System. The initiatives are designed to provide earlier detection of software defects, rapid integration of 3rd party software solutions, and better operational performance – all resulting in lower integration costs for the weapons system program.
Image Segmentation Using Method Of Edge Detection For Underwater Object Recognition
Dr Bogdan Zak, Polish Naval Academy, Poland
Step of image segmentation is an essential part of problem of object recognition on static images and video. Unfortunately, there are no ready recipes for carrying out the correct segmentation, and approaches to this problem depends mainly on the specific of recognized object. The operation of the segmentation is a multi-stage processing of input image using filtration techniques, mathematical morphology and binarization. The number, type and order of the used techniques depends on the following parameters of analyzed image: resolution, the level of noise, the background structure and dynamics of the edge of the recognition object. In this work the problem of object recognition is narrowed to recognize underwater objects. This assumption is determining the use of the digital image processing techniques, including the order of their execution. The presented method was developed in Matlab, using the built-in Image Processing Toolbox. The paper presents the steps of the algorithm with a discussion of techniques used in mathematical morphology, filtration and gradient methods. Also there are presented examples of the results of verification researches.
Energy Recovery To Reduce Fuel Consumption On Naval Ships
Mr Alexis Roy, DCNS, France
In the ecologic and economic context, this is a pre design system study about a recovery system which makes available energy to some ship’s ancillaries. Recovery equipments produce hot water to be used in subscribers to make cold water, fresh water, hot water and hot/cold air in an environmental friendly way (without any toxic emissions).
The design of recovery and subscribers equipments is evaluated for a Frigate type naval ship, obtaining main data at sketch step (weight and main dimensions, cost balance, ancillary balance).
Main military requirements must be taken into account: the system’s components mustn’t influence ship’s vulnerability. As each component is chosen on the shelf, standard ship’s equivalent equipment had to be kept but their number could be reduced.
Furthermore, the recovery allows exhaust temperature decrease which is favourable to infrared signature.
This study allows putting at first plan the constraint to match naval ship operational profile (mainly speed profile) with ancillary’s demands.
Besides, some of today on the shelf equipments are not available in a marine version and they require further developments efforts to adapt them to marine applications. This is especially the case of one of the main equipment of the system: the absorption machine which exists with very good results of operation on land application really needs its marine version.
Engagement Coordination Concepts for Joint and Combined Coalition Operations
Mr Wouter van der Wiel, TNO, Netherlands
How to coordinate engagements in a coalition setting where sharing of system engageability data is very limited?
Engagement coordination (EC) can currently be executed in various ways, from pre-planned responses to real-time exchange of information and orders through voice and data. In order to support the operator and decision maker with automated algorithms the need exists for sharing of system engageability data. In coalition situations sharing of these data is often very limited, for various reasons. Our approach to overcome this challenge is to develop, explore and compare new and existing EC concepts for use in coalition settings. These EC concepts make use of existing Link 16 messages as much as possible, but additionally provide a growth path to increased capabilities using extended Link 16 messages that include additional information.
Out of a series of seven EC concepts we focus on the decentralised bidding concept, the decentralised pre-planned responses concept and the centralised shared data concept. These concepts are analysed in a coalition setting with various scenarios for anti-ship sea skimming missile (maritime), cruise missile (joint and combined) and ballistic missile (joint and combined) threat.
The decentralised bidding concept aims at minimising the sharing of real-time information, down to one number: the bid.
The decentralised pre-planned responses concept aims at minimising the sharing of real-time information through multiple pre-planned responses. The centralised shared data concept aims at providing a commander with coalition engagement situational awareness.
Off-Hull Intermittent Connectivity Network Management Using Computational Intelligence
Mr. Steve Roodbeen, Naval Undersea Warfare Center (Division Newport), United States
Underway, a submarine and its crew are capable of generating vast amounts of information the off-hull significance of which varies depending on a number of factors that may include time for example. There is also a natural contention between functional capabilities (e.g., Combat Control) and/or operators regarding the importance of information. Since the available bandwidth of the off-hull communication channel is largely unpredictable, information exchange must be managed to ensure critical information receives precedence. Complicating the matter is the fact that composition of the critical information set varies as a voyage progresses. To mitigate, intelligent information exchange algorithms capable of managing the complexity of the underlying problem while providing the crew with a set of alternative exchange options are proposed.
This paper examines existing and emerging off-hull submarine communication technologies, describing a service oriented architecture (SOA)-based approach to aggregate distinct communication mechanisms. Further, the paper explores techniques to manage the composition of the off-hull transmission stream despite intermittent connectivity. One potential solution model is described, as well as solution approaches. The ultimate goal of the research outlined in this paper is to provide a novel capability to optimize the utilization of off-hull communication bandwidth as it becomes available.
Mine Counter Measures Capability Development
Mr. Loïc Tacher, DCNS, France
Mine Countermeasures are envisaged through all the more automated systems like UUVs or USVs carrying a variety of payloads.
Many candidate systems cause the capability planner a combinatory situation.
Developing a Mine Counter Measures capability is choosing among a variety of systems and binding them into a coherent architecture, able to cope with required operational scenarios.
This paper will illustrate an approach of dealing with this capability development, through a method that could be extended or adapted to other domains than Mine Warfare. In particular, a way to discuss operational ambitions against resources will be proposed.
Extreme Short HF Submarine Antennas (white paper)
Mr Frank Plonski, HI-Q ANTENNAS, United Kingdom
Abstract text to follow
Design and Classification of an Amphibious Naval Ship
Ing. Nico BRUNI, RINA Services SPA, Italy
Commander Mauro Galliussi, Italian Navy, Italy; Eng. Stefano Ferraris, Fincantieri Cantieri Navali Italiani S.p.A., Italy
Due to their versatility, Amphibious Naval Ships represent an ideal solution for Navies that are projected in worldwide operation both for military, peace-keeping or humanitarian scopes.
In fact, they are characterised by projection capabilities from sea, air and land thanks to the availability of well dock, flight deck and Ro-Ro spaces; when employed in military operations, they can also act as command and control centres.
The design of an Amphibious Naval Ship is to be such that it may easily be fitted for all the foreseen operating conditions: helideck and garage spaces are to be used also for vehicle or container transportation, accommodation spaces for troops may be employed as hospital areas in disaster relief, etc.
From classification point of view, an Amphibious Naval Ship presents a number of peculiar features that are unique for a military vessel; hull forms, carriage of vehicles and transportation of troops or civilians (when employed in humanitarian missions) constitute a link with merchant Ro-Ro pax ships but military features such as ammunition stores, flight deck, well dock, hangar and refuelling facilities require special consideration. In particular, the presence of a well dock represents a real big issue regarding stability approach and cannot be dealt with standard criteria.
This paper aims at giving an overview on a joint approach to the design and classification of such vessels, focused on the need to provide Navies reliable and fully operational ships through the most cost-effective configurations.
SeaCon AUV system - Technology Evaluation, Training and Development of Concepts of Operation for the Portuguese Navy
Mr. João Borges de Sousa, FEUP (Faculdade de Engenharia da Universidade do Porto), Portugal
Commander Carlos Carvalho Afonso, Portuguese Navy, Spain
This paper will describe the Seacon Autonomous Underwater Vehicle (AUV) system that is being developed by Porto University in cooperation with the Portuguese Navy under the Seacon project, funded by the Portuguese Ministry of Defense.
The main objective of this project consists of the development of an open and low cost AUV system for training and improvement of concepts of operation for shallow waters.
The system will also be used by the Portuguese Navy to test and evaluate underwater technologies in a cost-effective manner and to develop specialized underwater warfare know-how, namely in a mined environment.
The Seacon AUV system is based on evolutions of the award wining Light Autonomous Vehicle (LAUV) and of the Neptus command and control framework for networked vehicle systems, both developed by Porto University. The LAUV is a torpedo shaped vehicle made of composite materials (110x16 cm) with one propeller and 4 control fins. It has an advanced miniaturized computer system running modular controllers on a real-time Linux kernel. It is easily configurable for multiple operation profiles and sensor configurations to facilitate test and evaluation of new technologies. In the standard configuration it comes with a low-cost inertial motion unit, a depth sensor, a LBL system for navigation, GPS, GSM and WiFi. With Neptus vehicles, operators, and operator consoles come and go. Operators are able to plan and supervise missions concurrently.
Additional consoles can be built and installed on the fly to display mission related data over inter-operated networks. This is aimed at networked operations with other vehicle systems, such as air or surface autonomous vehicles.
Next Generation Chilled Water Plant For Navy Applications
Mr Matthieu Faucheux, Johnson Controls, France
By banning potentially ozone-depleting substances, the Montreal Protocol has driven substantial changes in refrigeration and air conditioning technology.
Simultaneously, a new geopolitical context has introduced the need for operation in warmer waters and for extremely quiet machines, especially for submarines. In the mean time, the “traditional” requirements for Navy chillers are anything but relaxed: high reliability, shock & vibration resistance, light weight, compact size, reduced levels of manning and maintenance… To comply with these conflicting requirements, the conventional refrigeration technologies have been thoroughly revisited, producing a new generation of navy specific water-chillers using centrifugal compressors driven by high-speed motors on magnetic bearings.
Today this technology is aproved by many Navies and installed with success on board nuclear submarines and frigates. York Navy Systems by Johnson Controls is now developping a special unit dedicated for Mine hunters.
Physical And Mathematical Problems Of High-Speed Hydrodynamics For Motion Of Supercavitating Bodies In Water
Dr. Vlaimir Serebryakov, Institute of Hydromechanics, National Academy of Sciences, Ukraine
The object of this study are key problems of high-speed hydrodynamics and dynamics of in-water motion of nearly axisymmetric supercavitating bodies, which are encountered during elaboration of technologies of motion of supercavitating vehicles of various types with the range of velocities ~75-500m/s, of inertial projectiles with the range of velocities ~300-2500m/s and of some industrial technologies.
Development of technologies based on supercavitation faces the necessityy of conducting long-term basic research in the field of supercavitation and a series of adjacent areas. The basis of these research studies is one of most challenging problem of mathematical physics for calculation of flows with initially unknown free boundaries with a large number of important physical manifestations and effects from the point of view of development of technological applications.
The main content of study is concentrated on the analysis of the following problems:
- Practical methods of calculation of axisymmetric and nearly axisymmetric cavitation flows;
- Problems of gas loss calculation including cases of complicated flow past a streamlined body;
- Calculation of ventilated stationary and no stationary cavitation flows;
- Calculations of gliding and interaction of various parts of the body hull with cavity walls;
- Possibilities and modes of drag reduction during body motion in a cavity;
- The analysis of existing capabilities of high-speed movers of hydro jet type and their interaction with a cavitation flow;
- The basic problems of the account of water compressibility at super high velocities of motion;
- Problems of calculation of dynamics and possibilities of steering of supercavitating bodies, including hydro-elastic effects, resonance frequencies, and strength estimations.
The work has been conducted with support of the London Office of the Naval Global Research, USA. Special thanks to Dr. Nicolas. Nechitailo and Dr. Clayton Stewart.
Ship Modularity Concepts and Application
Mr Marc DeBlasio, Northrop Grumman, United States
Modular Mission Packages (MPs) bring transformational focused capability to navy ships allowing increased flexibility by changing MPs to meet changing operational requirements. This concept is being implemented on the US Navy Littoral Combat Ship (LCS). Northrop Grumman, as the Mission Package Integrator (MPI), provides the USN with high-performance, modular, seamlessly
integrated MPs for the LCS. The result is a multi-role warship, facilitated through rearrangement of modular components sharing common design standards and network interfaces.
The modularity concept is applicable to all navies. The level of modularity is determined based on the ships, missions, and mission systems selected for application. Presentation will provide information on concept rationale and a road map for application to interested navies.