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System Optimization - I Multi-disciplinary Design Optimization. K Sudhakar PM Mujumdar Centre for Aerospace Systems Design & Engineering Indian Institute of Technology, Mumbai. Formal Process for Design. Requirements Capture Problem statement
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System Optimization - IMulti-disciplinary Design Optimization K Sudhakar PM Mujumdar Centre for Aerospace Systems Design & Engineering Indian Institute of Technology, Mumbai
Formal Process for Design • Requirements Capture Problem statement User, Regulatory, Implied, . . • Establish Concepts • Identify Modeling & Simulation Environment for System Analysis. Easy for familiar concepts. • Design Space Exploration for chosen concepts. Subjective, Parametric studies, Optimization, ? • Design Specification
Analysis Inputs Outputs System Analysis
Analysis Design Variables Requirements System Analysis Many designs may satisfy requirements. Goodness criteria?
Objective Analysis Design Variables Requirements as Constraints System Analysis
Objective Analysis Design Variables Requirements as constraints Change design Subjective? System Design
Analysis Geometry, Etc. Performance, Cost, Weight, System Analysis
Aerodynamics Structures Controls Trajectory Performance, Cost, Weight, Geomtery, Etc. Propulsion System Analysis Identify, validate and integrate modules
Sub-System Analysis Aerodynamics Aerodynamics
VLM for Lift CFD for drag Sub-System Analysis Aerodynamics Analysis - Recursion
DATCOM CFD Sub-System Analysis Aerodynamics Fidelity level of analysis - Low, Medium, High
System Modeling & Simulation • Requires great insight • Need to use most appropriate model • Occam’s razor • Integration of sub-system models • Issues in integration • Technical • Human • . . . . .
Integration Issues I cannot find the correct tuning parameters! Why do you want my program? System Designer’s Nightmare! I have a new version of analysis software You have to know my code to be able to execute it!
HW-6 Controls HW-7 Optimizers HW-3 System-II HW-1 Aerod HW-2 Struct HW-4 Prop HW-5 System-I Frameworks for Integration • Distributed analyses & ownership • System level virtual integration • System level vocabulary • Customized standard tools • eg. iSIGHT, Phoenix, • & CASDE Framework
System Analysis X1, Y2 A1 Y1 X2 A2 Y2 XS YS Y3 X3 A3 XS = {x1, x2, x3} YS = { y1, y2,y3 }
System Analysis X1, Y2 A1 ? Y1 X2 A2 Y2 XS = {x1, x2, x3} YS = { y1, y2,y3, x1 } Y3 X3 A3 How to execute A1?
x1 A1 Y1 y2 A2 x2 y2 YS = { y1, y2,y3 } x3 Y3 A3 System Analysis - Prescribed Scheduling
x2 A2 y2 y2 y1 A1 x1 YS = { y1, y2,y3 } x3 y3 A3 System Analysis
How to explore design space? • Brute force? How many function evaluations? • Evolutionary methods, derivative free - GA, SA! • How to compute derivatives? • Time intensive models • noisy models Surrogate models - DOE/RSM, DACE Variable Fidelity Methods Sensitivity Analysis
? Problem statement Modeling & Simulation environment Integrating models Sensitivity analysis (derivatives) Optimization technology etc.