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TITLE: Undersea Weapon Design and Optimization
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TITLE: Reduction of Military Vehicle Acquisition Time and Cost through
Advanced Modelling and Virtual Simulation [La reduction des couts et des
delais d’acquisition des vehicules militaires par la modelisation avancee et
la simulation de produit virtuel]
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Undersea Weapon Design and Optimization
Kam W. Ng
Office of Naval Research
800 North Quincy Street
Arlington, VA 22217, USA
This paper provides an overview of the Undersea Weapon Design and Optimization (UWDO) program
sponsored by the United States Navy’s Office of Naval Research (ONR). Progress, status, and future
research directions of the UWDO program are presented. The objective of the UWDO program is to
develop computational tools and simulation-based methodology to optimize undersea weaponry system
designs with respect to cost and performance. The design tools and environment developed in this
program continue to be improved and implemented in the ONR Torpedo Guidance & Control, Undersea
Warheads/Explosive, Torpedo Stealth, and High-Speed Supercavitating Undersea Weapons programs.
Specifically, the design tools and collaborative design environment are used for the design of torpedo
sonar system, new warhead configurations, virtual acoustic design using active control techniques, cost
analysis, and simulation of high-speed supercavitating weapons in the virtual environment. Lastly,
recommendations and future research directions in UWDO are provided.
The objective of the UWDO program is to develop computational tools and simulation-based
methodology to optimize undersea weapon system designs with respect to cost and performance. UWDO
is the infrastructure that is being developed to support the design of various undersea weapons as shown
in Figure 1. The weapons include the High-Speed Quick Reaction, Torpedo Defense, Coordinated
Attack, Long Range Stealth, and Advanced Weapons. These undersea weapons cover close-in and
extended range scenarios, with affordability as the key requirement.
The UWDO program is based on the Simulation Based Design (SBD) approach. As shown in Figure 2,
SBD spans the design, prototyping, acquisition, and operations of undersea weapons. Specifically, it is
used in the simulation-based design and engineering, virtual manufacturing, virtual testing , training
simulations, operations and logistics simulations, and warfare analyses.
The UWDO system architecture (as depicted in Figure 3) consists of four major components- multi-user
access server, design tools, simulation environment, and life cycle factors. The multi-user access server is
the project data manager that communicates and interacts with the other three components. The design
tool consists of analytical and numerical models, computer codes, and technology object library that
supports product design and development. The simulation environment provides performance simulation
and virtual training, testing, and tactics evaluation. The life cycle factors component deals with logistics
modeling, cost modeling and analyses, and manufacturing process modeling
The ONR UWDO team consists of members from the Naval Undersea Warfare Center- Newport
Division, Pennsylvania State University/ Applied Research Laboratory, Naval Surface Warfare Center-
Indian Head Division, Science Application International Corporation (SAIC), SRI International, Georgia
Institute of Technology, and University of Maryland.
Paper presented at the RTO AVT Symposium on “Reduction of Military Vehicle
Acquisition Time and Cost through Advanced Modelling and Virtual Simulation”,
held in Paris, France, 22-25 April 2002, and published in RTO-MP-089.
Affordable Science & Technology (S&T) product development, acquisition, and support for future
undersea weaponry requires a software driven simulation based design process that provides:
1) improved (reduced time and cost) product development, 2) a good cost and benefit estimate of new
technologies to meet future war-fighting needs, and 3) efficient transition of technology to the end users.
The UWDO program develops the infrastructure that supports the development of undersea weapons in
torpedo guidance and control, warhead, propulsion, stealth, and torpedo defense technologies, as well as
advanced weapons system concepts such as the high-speed supercavitating weapons. This program
establishes a modeling and simulation environment that integrates the United States Navy’s S&T with
Engineering Development efforts in undersea weaponry. The goal of the UWDO project is to develop a
system that determines the design that gives optimal performance with a minimal Total Ownership Cost
Some of the key technical challenges and S&T issues include:
• Interface of the various design tools and computer codes
• Connectivity of multi-users in a collaborative design environment
• Affordable, optimized designs
• Effective visualization of large amounts of data
Collaborative and Distributive Design Environment
The UWDO program focuses on the development of system architecture and design tools for the
collaborative and distributive design environment. Design tools such as a virtual prototype design,
Multidisciplinary Optimization (MDO), and cost/performance analyses are emphasized. Cost and
performance trade-off studies are conducted by applying the methodology and tools to rapid prototyping
of a torpedo upgrade, a new capability, or a new weapon system design. Figure 4 illustrates the virtual
prototyping of a torpedo. Given overall system attributes in speed, depth and range, the designers can
select the subsystems in power, guidance & control, propulsor, hydrodynamics, shell and structures, and
payload. Cost analyses and simulated engagements are then performed to determine the optimal design.
Connectivity needs to be developed for disparate languages, Computer Aided Design (CAD) systems,
performance models, external libraries, and users. Boyars et al.  identified connectivity among
designers and users as one of the key requirements for the collaborative and distributive design
environment. The design and optimization process involves building the SBD architecture using physics-
based models to provide data for process/mechanical/environmental simulations, which, in turn, forms the
basis for the vehicle subsystems, and creates a virtual prototype system design that can be used for
performance, cost, and quality assessment. As an example, a web based collaborative and distributive
design environment was used to design a torpedo sonar array (Figure 5). Engineering analyses and design
were performed by geographically dispersed designers/users.
Multidisciplinary Optimization (MDO) helps the users and designers to gain the understanding of the
interaction among the various components to make effective and efficient tradeoff decisions. Kusmik 
used MDO, and Belegundu et al.  used attributed-based MDO to design undersea vehicles. MDO
needs a rapid convergence on optimal system-level design using the various models, simulation tools, and
information management systems. Considering the conflicting requirement of the various sub systems
and components, such optimization is indeed very complicated. Research efforts in Interval
Programming and Probabilistic Methods are underway to develop effective and fast algorithms for
Multi-objective MDO is being used for a new warhead design (Figure 6). Given the design requirements,
and objectives and constraints, the optimizer interacts with the warhead server, torpedo shell analyzer and
lethality evaluator to produce the optimal warhead design. In this optimization, warhead lethality,
radiated noise, and probability of kill (P k ) are considered simultaneously.
In the electric propulsion design and analysis, thermal and structural analyses are performed
simultaneously to optimize motor design. As shown in Figure 7, thermal analysis and finite element
analysis are integrated in the motor design.
Total Ownership Cost (TOC) has become one of the critical criteria in the weapon system acquisition
process. TOC consists of costs from: 1) research and development, 2) production and manufacturing, 3)
operation, and 4) maintenance. There are commercial parametric cost estimating software and cost
models, e.g., PRICE, CORBA, for cost analyses , Typical cost estimation requires inputs such as
design, schedule, and deployment information. The outputs of cost estimation consist of total program
cost, cost by phase, cost by type, and cost by category. The cost by category includes drafting, design,
system engineering, project management, prototype, production, tooling & test equipment, general &
administrative, and overhead. Maintenance cost is one of the most challenging cost estimations, in
particular when there is a lack of repair records or cost data.
Virtual Design Environment
Recently, substantial progress has been made in virtual reality and scientific visualization to translate
large amounts of data to visual representation. Aukstakalnis and Blatner  defined Virtual Reality as “ a
way for humans to visualize, manipulate and interact with computers and extremely complex data.” The
virtual design environment provides visualization techniques that designers can see design changes and
their impact on the overall system.
Virtual reality and collaborative design environment is used for the development of advanced undersea
weapons. Specific interests and focus are on torpedo stealth, warhead design, and high-speed
supercavitating weapons. For example, the Virtual Reality Laboratory at the University of Maryland is
developing the active noise and vibration control techniques  for stealth torpedo using this approach
(Figure 8). Numerical results from the finite element model of the torpedo shell are displayed in the
virtual environment. The animated structural noise radiation can be heard using the sound system and the
vibration of the shell can be felt with the touch glove.
With the virtual environment, designers can select a range of subsystem technologies to assemble a
conceptual design. This virtual prototyping capability dramatically reduces development time and total
ownership cost. The virtual environment provides simulation and modeling capabilities, as well as
evaluation of realistic operational scenarios.
The immersive visualization facilities at the Penn State University/ Applied Research Laboratory, Virginia
Tech, and University of Maryland, are utilized together with basic and applied research related to
supercavitation physics, torpedo silencing and warheads to develop a unique integrated design
environment. The three virtual reality sites are connected to form a collaborative design cluster among
UWDO team members. The capability to visualize real-time simulations of the high-speed
supercavitating weapons has been demonstrated at the Penn State University’s Applied Research Lab.
Modeling and simulation capabilities are augmented with the capability to generate immersive
simulations from a synthesis of individual subsystem designs. Collaborative design architecture, multi-
disciplinary optimization scheme, cost analysis tools and other relevant subsystem synthesis methods are
incorporated into this virtual design environment. The advanced weapon designs are evaluated in
operational scenarios modeled using the concept of operations requirements from the operational Naval
community. Standard protocols are utilized so that the conceptual designs can be evaluated in warfare
simulation involving real players. This virtual design environment provides a faster, more effective, and
affordable design space to develop undersea weaponry to meet future threats.
Recommendations and Future S&T Directions
Simulation Based Design (SBD) is an effective approach for system design and product development.
The UWDO environment provides the foundation for timely, information-based engineering and
Future S&T directions should focus on Multidisciplinary Optimization, cost analysis, and virtual
environment for simulation. Specifically, the following areas should be of great interests:
• Efficient optimization schemes
• Fast convergence algorithms
• Accurate cost analyses
• Representation and interaction with large amounts of digital data in the virtual environment
• Interfacing design tools and computer codes
 Hanneman, A. B. and Henderson, R. E., Visualization, Interrogation, and Interpretation of Computed
Flow Field- Numerical Experiments, AIAA Paper 2000-4089, 2000.
 Boyars, A. B., Kusmik, W. A., and Yukish, M., Collaborative Engineering Across Organizational
Boundaries, ASNE Conference, April 2002.
 Kusmik, W. A., Optimization in the Simulation Based Design Environment, ASME DETC Paper,
Pittsburgh, PA, September 2001.
 Belegundu, A. D., Halberg, E., Yukish, M. A. and Simpson, T. W., Attribute-Based Multidisciplinary
Optimization of Undersea Vehicles, AIAA Paper 2000-4865, 2000.
 Yukish, M., Cost Analysis, 54th MPFT Meeting, Virginia Beach, VA, April 2000.
 Aukstakalnis, S. and Blatner, D., Silicon Mirage: The Art and Science of Virtual Reality, Peachpit
Press, Berkeley, California, 1992.
 Akl, W. and Baz, A., Design of Quiet Underwater Shells in a Virtual Reality Environment, AIAA
Paper, Atlanta, GA, September 2002.
Discussor's Name: Professor Ramana Grandhi
Author's Name: Dr. Kam W. Ng
Q: You are doing research in multidisciplinary optimization and also in probabilistic mechanics. Are you
doing any work where the probabilistics is combined in MDO or reliability optimization or MDO based
on stochastic finite element analysis?
A: We do multidisciplinary optimization, and modeling using the various numerical techniques including
finite element analysis. We also use probabilistic methods in the undersea weapon design. Our design
methodology is based on integrated system approach. Accordingly, we combine the various numerical
techniques, computer codes and tools in the multidisciplinary optimization.
I High Speed,
Advanced I Quick
Weapons 1 Reaction
Enabling Technologies such as
Affordability Impact all Capabilities
Figure 1. Capabilities of Undersea Weapons
and Life Cycle Cost
DESIGN , PROTOTYPING, Am
k— OPERATIONS N-.
DEFINITION ^ MANUFACTURING
The SBD VISION: Develop, manufacture, deploy, and operate weapons “in the
computer” in a fraction of the current time and at a fraction of the current cost.
Figure 2. Simulation Based Design (SBD) Vision
SIMULA TION ENVIRONMENT
Figure 3. Design System Architecture
Overall System Attributes
Subsystem Technology Choices
Guidance & Control
• Heated Laminar Flow
• Suction Laminar Flow
Shells & Structures
• Any Material, Al Default
• Pump Jet
• Integrated Motor-Propulsor
• Bulk Charge
• MK50 Warhead
• Estimate Cost
• Engineering Analysis
• Simulated Engagements
Figure 4. Undersea Weapon Design
• Establish a web based collaborative environment for distributed team access to program data
— Technical data
— Program schedules and correspondence
• Modeling services applied for design development
— Solids Based Design
• Geographically dispersed design reviews
• Implement paperless processes
• Web based program management and workflow
• Model transitions to life cycle support functions
Virtual Reality Modeling Language (VRML) design model with intelligent web based interface
Figure 5. Application to Torpedo Sonar Design
• WARHEAD TYPE
• BULK EXPLOSIVE TYPE
• SHAPED CHARGE EXP.TYPE
• WARHEAD LENGTH
• SHELL MATERIAL
• MAX. DEPTH
• Pki . ”■ . f*Kn
• WEIGHT OF WARHEAD
• RADIATED NOISE
Figure 6. Multi-Objective Multidisciplinary Design Optimization for 'Warhead
UWDO Electric Motor Model
VRML on WebSite
3D Solid Model
Finite Element Analysis
Figure 7. Electric Propulsion Design and Analysis
Actuator Active Rib Damping
Figure 8. Virtual Acoustic Design of Torpedo Hull