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UNCLASSIFIED 



Defense Technical Information Center 
Compilation Part Notice 

ADP014188 

TITLE: Undersea Weapon Design and Optimization 

DISTRIBUTION: Approved for public release, distribution unlimited 
Availability: Hard copy only. 



This paper is part of the following report: 

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] 

To order the complete compilation report, use: ADA415759 

The component part is provided here to allow users access to individually authored sections 
of proceedings, annals, symposia, etc. However, the component should be considered within 
the context of the overall compilation report and not as a stand-alone technical report. 

The following component part numbers comprise the compilation report: 

ADP014142 thru ADP014198 



UNCLASSIFIED 




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Undersea Weapon Design and Optimization 



Kam W. Ng 

Office of Naval Research 
800 North Quincy Street 
Arlington, VA 22217, USA 

ngk@onr.navy.mil 



Abstract 

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. 

Introduction 

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 [1], 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. 




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Technical Challenges 

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 
(TOC). 

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. [2] 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 

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 [3] 
used MDO, and Belegundu et al. [4] 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 
optimization. 




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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. 

Cost Analysis 

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 [5], 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 [6] 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 [7] 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 




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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 
programmatic decision-making. 

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 

References 

[1] Hanneman, A. B. and Henderson, R. E., Visualization, Interrogation, and Interpretation of Computed 
Flow Field- Numerical Experiments, AIAA Paper 2000-4089, 2000. 

[2] Boyars, A. B., Kusmik, W. A., and Yukish, M., Collaborative Engineering Across Organizational 
Boundaries, ASNE Conference, April 2002. 

[3] Kusmik, W. A., Optimization in the Simulation Based Design Environment, ASME DETC Paper, 
Pittsburgh, PA, September 2001. 

[4] Belegundu, A. D., Halberg, E., Yukish, M. A. and Simpson, T. W., Attribute-Based Multidisciplinary 
Optimization of Undersea Vehicles, AIAA Paper 2000-4865, 2000. 

[5] Yukish, M., Cost Analysis, 54th MPFT Meeting, Virginia Beach, VA, April 2000. 

[6] Aukstakalnis, S. and Blatner, D., Silicon Mirage: The Art and Science of Virtual Reality, Peachpit 
Press, Berkeley, California, 1992. 

[7] Akl, W. and Baz, A., Design of Quiet Underwater Shells in a Virtual Reality Environment, AIAA 
Paper, Atlanta, GA, September 2002. 



Paper #49 

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. 




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Force Multipliers 
& Flexibility 



I High Speed, 
Advanced I Quick 

Weapons 1 Reaction 



LLong Range 
ft Stealth 



Extended R; 
Prosecution 



if Torpedo 
f Defense 



Coordinated 

Attack 



Close-In 

Encounters 



Enabling Technologies such as 
Affordability Impact all Capabilities 



Figure 1. Capabilities of Undersea Weapons 





Enhanced Weapon 
Effectiveness 

Reduced Acquisition 
and Life Cycle Cost 
Streamlined 
Technology Insertion 

Documented 

“On-the-Shelf” 

Capabilities 

Reduced 
Development 
Cycle Time 
Rapid Prototyping 
and Deployment 



DESIGN , PROTOTYPING, Am 



LESSONS 

LEARNED 



OPERATIONS 

k— OPERATIONS N-. 
& LOGISTICS 
SIMULATIONS 

i 



WARFARE 

ANALYSES 






REQUIREMENTS 



SIMULATION 
BASED 
DESIGN & 
ENGINEERING 



PRODUCT VIRTUAL 

DEFINITION ^ MANUFACTURING 



ENVIRONMENTAL 

MODELING 



VIRTUAL 

TESTING 



DEPLOYABLE 

SYSTEM 



TRAINING 

SIMULATIONS 



OPERATIONAL 

SYSTEM 



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 







49-6 



SIMULA TION ENVIRONMENT 




Figure 3. Design System Architecture 



Overall System Attributes 



• Speed 

• Depth 

• Range 




Subsystem Technology Choices 

Power 

* Conventional 



• Electric 

• Hydrox 
Guidance & Control 

• MK50 

• ADCAP 

• Others 



Hydrodynamics 

• Conventional 

• Heated Laminar Flow 

• Suction Laminar Flow 

Shells & Structures 

• Monococque 

• Any Material, Al Default 



Propulsor 

• Pump Jet 

• Integrated Motor-Propulsor 






Payload 

• Bulk Charge 

• MK50 Warhead 



7 




• Estimate Cost 

• Engineering Analysis 

• Simulated Engagements 



Figure 4. Undersea Weapon Design 








49-7 



• Establish a web based collaborative environment for distributed team access to program data 

— Design 
— Analysis 
— Technical data 

— Program schedules and correspondence 

• Modeling services applied for design development 

— Thermal 
— Structural 
— Solids Based Design 
— Shock 

• 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 



DESIGN: 

• WARHEAD TYPE 

• BULK EXPLOSIVE TYPE 

• SHAPED CHARGE EXP.TYPE 

• WARHEAD LENGTH 
•VEHICLE DIAMETER 

• SHELL MATERIAL 

• MAX. DEPTH 



OPTIMIZER 

(M-MDO) 



OBJECTIVES/CONSTRAINTS: 

• 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 



Thermal Analysis 



Finite Element Analysis 



ANSYS 



Figure 7. Electric Propulsion Design and Analysis 



Actuator Active Rib Damping 



Propulsor 



Figure 8. Virtual Acoustic Design of Torpedo Hull