Framework for MDO Studies Amitay Isaacs Center for Aerospace System Design and Engineering IIT Bombay

What Is MDO Framework? Automation Integration of disciplinary analyses Integration of various optimizers Allow multiple optimization techniques Graphical user interfaces Evaluate trends and sensitivity Data visualization

MDO Framework Requirements Architectural design Problem formulation construction Problem execution Information access

Architectural Design Provide intuitive GUI Object-oriented principles Extensible and support for developing interfaces for adding new programs No unreasonable amount of overheads Handle large size problems Support collaborative design Framework design should be based on standards

Problem Formulation Construction Configure complex branching and iterative problem formulations easily Easily reconfigure existing problems Support legacy and proprietary codes Support multiple optimization methods including multilevel schemes Provide debugging support for multiple processes executing across computers on the network

Problem Execution Automate execution of processes and movement of data Execute multiple processes in parallel Support execution distributed across network of heterogeneous computers User interaction (steering) during design cycle Operate in batch mode

Information Access Provide database management features Capability to visualize intermediate and final optimization and analysis results Monitoring capability for viewing the status of an execution and system status Mechanisms for fault tolerance

Multi-disciplinary System Integration 1.Common vocabulary –Data is identified using unique variable names (e.g. span or wingspan) across disciplines Data Dictionary

Multi-disciplinary System Integration 2.Easy integration of analysis modules –Source code availability –Commercial/legacy codes –Persistence of analysis state during subsequent executions Analysis Wrappers

Disciplinary Analysis Module Wrapper Data Server Disciplinary Analysis Routine Input Wrapper Output Wrapper Available Source Code

Disciplinary Analysis Module Wrapper Data Server Input Processor Output Processor Legacy Disciplinary Code Input File Output File

Disciplinary Analysis Module Wrapper Data Server Input Processor Commercial Disciplinary Code Input File Output Wrapper STAR-CD

Multi-disciplinary System Integration 3.Data exchange –Provide data communication mechanism between analysis modules –Coupling with optimizers Data Server

Data Server and Analysis Wrapper Data Server Input Processor Output Processor Legacy Disciplinary Code Input File Output File

Data Server for Data Exchange Disciplinary Analysis Input Wrapper Output Wrapper Data Server Read “Length” Read “Height” Read “Width” VOL = L * H * W Write “Volume”

Multi-disciplinary Analysis Process 1.Build the data dictionary 2.Collect all the analysis modules Build wrappers for all analysis modules Register in the framework 3.Design the system problem Specifying data dependency Providing execution sequence (optional)

Multi-disciplinary System Analysis Data Server Sequence of Execution Analysis 2Analysis 3Analysis 4 Initial Data Result 6 Analysis 1

Multi-disciplinary Design Process 4.Specify optimization problem Identify design variables Specify objective, constraints Provide initial design 5.Solve the problem 6.Visualize results

MDO Framework Architecture Database Configuration Execution Manager Sequence Logic MDO Controller Status/Log Handler Data Server OPT1 Optimizer Manager OPT2OPT3 AM1 Agent AM2AM3 GUI

Status/Log Handler Database GUI Configuration MDO Controller Execution Manager Sequence Logic Data Server OPT1 Optimizer Manager OPT2OPT3 MDO: Collecting Analysis Modules AM1 Agent AM2AM3

AM1 Agent AM2AM3 MDO Controller Execution Manager Sequence Logic Data Server OPT1 Optimizer Manager OPT2OPT3 MDO: Specifying Problem GUI Configuration Database Status/Log Handler

Stages in Using MDO Framework Building data dictionary Registration of analysis modules in the framework Problem definition Problem execution Visualization of results

Framework Modules - 1 Configuration manager –Registration of analysis modules and problem definition –Interface between user interface(GUI, agent) and the backend databases –Allows user to specify problem –Uses MDO controller for problem execution

Framework Modules - 2 MDO controller –Implements different MDO architectures –Uses execution controller to solve the problem Optimizer manager –Keeps track of available optimizers –Ease of use of different optimizers

Framework Modules - 3 Agent –Process running on each computer where analysis modules are located –Verifies availability of each analysis module for computation and updates status handler –Keeps updating status handler with current system load

Framework Module - 4 Status/log handler –Keeps track of all framework modules –Maintains system load info which is updated by each agent –Logs all the events in the framework –Keeps record of all the analysis executions

Framework Modules - 5 Sequence logic –Based on MDO architecture determines the sequence of analysis executions –Decides if the module could be run in parallel Execution manager –Schedules executions of analysis modules based on its availability and load on different machines –Can be triggered from command line to support batch processing

Framework Modules - 6 Data server –Allows exchange of data between different analysis modules –Stores history of all the solutions –Takes a snapshot of all variables to allow restart of problem execution

Framework Modules - 7 Database –Stores information about all registered analysis modules –Stores problem definitions –Stores optimized solutions

Framework Modules - 8 Graphical User Interfaces (GUIs) –Building wrappers for analysis modules –Registration of analysis modules –Problem definition –Execution and status information –Visualization

Roadmap for MDO Framework Medium fidelity analysis modules VLM EPM High fidelity analysis modules CFD (STAR-CD) FEM (MSC-NASTRAN)

MDO Problems To Be Attempted Wing design (focus on aeroelasticity) 3D duct design MAV design

Framework development plan Integration of STAR-CD, NASTRAN Support distributed computing GUI for problem setup and execution Basic visualization tools Implementation by December 2003

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