1. February 7, 2002MDO - 0 Aero India 2003, Bangalore Multidisciplinary Design Optimization Activities at CASDE, I I T, Bombay K Sudhakar & PM Mujumdar Centre for Aerospace Systems Design & Engineering Department of Aerospace Engineering, IIT Bombay Presentation at Aero-India 2003, International Seminar February 7, 2003

2. February 7, 2002MDO - 1 Aero India 2003, Bangalore

3. February 7, 2002MDO - 2 Aero India 2003, Bangalore Has MDO Been Around? B-707 DC-8 B-747 L-1011 B-767 A-300 AIAA-97-1408 Improvement in Aerodynamics siphoned off for other system level benefits – MDO in action

4. February 7, 2002MDO - 3 Aero India 2003, Bangalore Multi-disciplinary Design Optimization  Low fidelity models  Tightly coupled inter-disciplinary codes  All or most of the following, -High fidelity models -Formal Optimization -Disciplinary authority -Interdisciplinary couplings formally modeled/retained -Design freedom to significantly affect system performance in multiple disciplines simultaneously

5. February 7, 2002MDO - 4 Aero India 2003, Bangalore MDO Growth Over the Years & Structural Optimisation. 1982 : Holt Ashley AIAA lecture "Making Things Best..." "There are over 8073 papers in Optimal Control, AerodynamicOptimisation Not one paper on Optimization in Aircraft Design” 1991 : AIAA White Paper on MDO; & Special issue of Journal of Aircraft 1996 : Over 200 papers on MDO application to A/C Design, including from Industry 1998 : AIAA White Paper on MDO. “Summary of Industry MDO Applications & Needs”, Geising&Barthelemy 1999 : Second Special Issue of Journal of Aircraft

6. February 7, 2002MDO - 5 Aero India 2003, Bangalore Industry Application of MDO Source: AIAA MDO White Paper, 1998 Reproduced with permission

7. February 7, 2002MDO - 6 Aero India 2003, Bangalore Aug 1999 - CASDE initiates MDO activities Aug 2000 - First meeting of SIG-MDO Jan 2001 - Professional Development Course on MDO Jun 2002 - Second meeting of SIG-MDO, Workshop on MDO Feb 2003 - Third Meeting of SIG-MDO Sep 2003 - International Conference on MDO MDO@CASDE Over the Years

8. February 7, 2002MDO - 7 Aero India 2003, Bangalore Design / MDO Studies @CASDE AEW System Level Optimization Aero-elastic Design of Transport A/C wings Aircraft Intake (3D-Duct) design Low Fidelity Analysis High Fidelity Analysis (CFD) For more information http://www.casde.iitb.ac.in/MDO/

9. February 7, 2002MDO - 8 Aero India 2003, Bangalore RotodomePlatformRadarHeat exchanger AEW System P, H, V, C L Mission D2 D3 P H, V D4 H, V, C L D1 E W HX C D,H D, TL, WEWRWR QrB Ant L Ant W Ant W Rot C D,R W ds User requirements DC Design Optimization of AEW

10. February 7, 2002MDO - 9 Aero India 2003, Bangalore Stage I : Analysis based on empirical formulae Stage II : semi-empirical analysis realistic aerodynamic loading - VLM simplified structural analysis - EPM Stage III : Hi-fidelity analysis with aeroelasticity VLM FEM - NASTRAN MDO of Transport Aircraft Wing

11. February 7, 2002MDO - 10 Aero India 2003, Bangalore Design Problem ~150 seater aircraft Mission profile shown B 737-200 candidate for numerical study 12 34 5 6 78 Takeoff at sea level d ≤ 2150 m Climb to 11000 m at best ROC ≥ 11 m/s Loiter 45 min (Reserve) Land at sea level d ≤ 1220 m Descend to 1500 m Cruise for 3000 Km at best range M ≥ 0.74

12. February 7, 2002MDO - 11 Aero India 2003, Bangalore Simultaneous aerodynamic and structural optimization variables - wing aerodynamic shape + wing structural sizing constraints - mission, aerodynamics, structural, aeroelastic Optimizers : FFSQP / NPSOL (SQP) Aerodynamic analysis : Vortex Lattice Method (VLM) Structural analysis : Medium fidelity – Equivalent Plate Method (EPM) High fidelity – Finite Element Method (MSC NASTRAN) MDO of Transport Aircraft Wing Analysis tools MDO Problem

13. February 7, 2002MDO - 12 Aero India 2003, Bangalore Aerodynamic Geometry Planform Geometric Pre-twist Camber Wing t/c y x single sweep, tapered wing divided into stations S, AR,,  c itp b/2  c root AR = b 2 /S = c itp / c root Wing stations MDO of Transport Aircraft Wing

14. February 7, 2002MDO - 13 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Structural Geometry Cross-section Box height Skin thickness Spar/ribs y A A A x A symmetric front, mid & rear boxes r 1, r 2 l1l1 l2l2 c r 1 = l 1 /c r 2 = l 2 /c

15. February 7, 2002MDO - 14 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Function Evaluations Structural Stresses (  x,  y,  xy ) Structural Weight (Wt) Deformation Function (W(x,y)) / Nodal displacements Aerodynamic & Mission C L,sectional C l, C Di (VLM) M div (semi-empirical) & C Do (empirical) V stall,, Takeoff & Landing Distance Ceiling, ROC, Cruise Mach No. Geometric Fuel volume (V f )

16. February 7, 2002MDO - 15 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Loads Load case - quasi-static pull-up maneuver Aerodynamic pressure loads Engine loads Inertia Relief Fuel Weight Inertia Relief Wing Mass Inertia Relief Both are distributed as equivalent uniform pressures over wing stations

17. February 7, 2002MDO - 16 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Aerodynamic A rs tsts h’2h’2 h’1h’1 h root r2r2 r1r1 d/ch/c ii AR W/S StructuralAerodynamic System Analysis Structural VfVf Wt  M dd d to RCLCL ClCl C do

18. February 7, 2002MDO - 17 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Aerodynamic A rs tsts h’2h’2 h’1h’1 h root r2r2 r1r1 d/ch/c ii AR W/S StructuralAerodynamic Structural VfVf Wt  M dd d to RCLCL ClCl VLM FEM C do

19. February 7, 2002MDO - 18 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Aerodynamic A rs tsts h’2h’2 h’1h’1 h root r2r2 r1r1 d/ch/c ii AR W/S StructuralAerodynamic Structural VfVf Wt  M dd d to RCLCL ClCl VLM FEM C do

20. February 7, 2002MDO - 19 Aero India 2003, Bangalore MDO of Transport Aircraft Wing Aerodynamic A rs tsts h’2h’2 h’1h’1 h root r2r2 r1r1 d/ch/c ii AR W/S StructuralAerodynamic Structural VfVf Wt  M dd d to RCLCL ClCl VLM FEM C do Fidelity level for M dd and C do ?

21. February 7, 2002MDO - 20 Aero India 2003, Bangalore Optimizer FSQP INTERFACEINTERFACE History Block Input Processor Output Processor Aerodynamics (VLM) Structures MSC/ NASTRAN NASTRAN Interface Analysis Block Aeroelasticity Iterator Optimization Framework Architecture MDO of Transport Aircraft of Wing

22. February 7, 2002MDO - 21 Aero India 2003, Bangalore MDO of Transport Aircraft Wing For more information http://www.casde.iitb.ac.in/MDO/ Contact : mujumdar@aero.iitb.ac.in

23. February 7, 2002MDO - 22 Aero India 2003, Bangalore 3D-Duct Design Composite team ADA, Bangalore ARDB Associate Node for CFD, IIT Bombay ARDB CASDE, IIT Bombay Bring in CFD into Optimization loop Commercial codes? In-house codes?

24. February 7, 2002MDO - 23 Aero India 2003, Bangalore 3-D Duct Design Design Problem in Brief Entry Exit Location and shape known Geometry of duct from Entry to Exit ? Pressure Recovery? Distortion? Swirl?

25. February 7, 2002MDO - 24 Aero India 2003, Bangalore Parametrization Y X Z X Duct Centerline A X Control / Design Variables Y m, Z m A L/3, A 2L/3 Cross Sectional Area

26. February 7, 2002MDO - 25 Aero India 2003, Bangalore Parametrization Y X Z X Duct Centerline A X Control / Design Variables Y m, Z m A L/3, A 2L/3 Cross Sectional Area

27. February 7, 2002MDO - 26 Aero India 2003, Bangalore Typical 3D-Ducts

28. February 7, 2002MDO - 27 Aero India 2003, Bangalore 3D-Duct Design Using Low Fidelity Analysis Low Fidelity Design Criteria (Constraints) Wall angle < 6° Diffusion angle < 3° 6 * Equivalent Radius < ROC of Centerline Low fidelity analysis for pressure recovery (Objective function) No low fidelity analysis for distortion or swirl For results & discussion http://www.casde.iitb.ac.in/MDO/3d-duct/

29. February 7, 2002MDO - 28 Aero India 2003, Bangalore 3D-Duct Design Using High Fidelity Analysis Low Fidelity Design Criteria (Constraints) Wall angle < 6° Diffusion angle < 3° 6 * Equivalent Radius < ROC of Centreline CFD (Fluent) for pressure recovery & distortion Doyle Knight’s Group @Rutger’s University Optimization of width-depth of bump for minimising distortion. Grid quality required to capture distortion?

30. February 7, 2002MDO - 29 Aero India 2003, Bangalore 3D-Duct Design Using High Fidelity Analysis ? X 1-MIN X 1-MAX X 2-MAX X 2-MIN Domain for search using high fidelity code is large

31. February 7, 2002MDO - 30 Aero India 2003, Bangalore 3D-Duct Design Using High Fidelity Analysis Low Fidelity Design Criteria Wall angle < 6° Diffusion angle < 3° 6 * R EQ < ROC Fluent for CFD RSM / DOE DACE X 1-MIN X 1-MAX X 2-MAX X 2-MIN

32. February 7, 2002MDO - 31 Aero India 2003, Bangalore 3D-Duct Design Using High Fidelity Analysis Low Fidelity Design Criteria Wall angle < 6° Diffusion angle < 3° 6 * R EQ < ROC Fluent for CFD RSM / DOE DACE X 1-MIN X 1-MAX X 2-MAX X 2-MIN http://www.casde.iitb.ac.in/MDO/3d-duct/ anil@aero.iitb.ac.in sudhakar@aero.iitb.ac.in

33. February 7, 2002MDO - 32 Aero India 2003, Bangalore MDO Framework Easy integration of analysis modules Support for distributed analysis Optimization environment... Salas & Townsend AIAA-98-4740 Commercial Frameworks are available

34. February 7, 2002MDO - 33 Aero India 2003, Bangalore Why do you want my program? I have a new version of analysis software You have to know my code to be able to execute it! (it’s all in Russian) System Designer’s Nightmare! I cannot find the correct tuning parameters! MDO Framework Issues

35. February 7, 2002MDO - 34 Aero India 2003, Bangalore MDO Framework Issues Aerodynamics Expert Structures Expert Controls Expert System Analysis Analysis codes should reside with experts. System analysis should execute analysis codes on experts’ computers.

36. February 7, 2002MDO - 35 Aero India 2003, Bangalore Framework Development @CASDE Distributed computing (CORBA based) Database driven Tools to integrate analysis modules using wrappers Automatic data exchange between analysis modules amitay@aero.iitb.ac.in

37. February 7, 2002MDO - 36 Aero India 2003, Bangalore Framework Architecture Database Configuration Manager Execution Manager Sequence Logic MDO Controller Name Server Data Server OPT1 Optimizer Manager OPT2OPT3 AM1 Analysis Manager AM2AM3 GUI

38. February 7, 2002MDO - 37 Aero India 2003, Bangalore Optimization Issues Gradient based optimization Evaluation of gradients? Finite Difference. Requirements on convergence more severe than that required for engineering analysis. Noisy functions? X f

39. February 7, 2002MDO - 38 Aero India 2003, Bangalore User Supplied Gradients Complex Analysis Code in Fortran Manually extract sequence of mathematical operations Code the complex derivative evaluator in Fortran Manually differentiate mathematical functions - chain rule FORTRAN source code that can evaluate gradients

40. February 7, 2002MDO - 39 Aero India 2003, Bangalore User Supplied Gradients Manually extract sequence of mathematical operations Use symbolic math packages to automate derivative evaluation Code the complex derivative evaluator in Fortran Complex Analysis Code in FORTARN FORTRAN source code that can evaluate gradients

41. February 7, 2002MDO - 40 Aero India 2003, Bangalore User Supplied Gradients Parse and extract the sequence of mathematical operations Use symbolic math packages to automate derivative evaluation Code the complex derivative evaluator in Fortran Complex Analysis Code in FORTARN FORTRAN source code that can evaluate gradients

42. February 7, 2002MDO - 41 Aero India 2003, Bangalore Gradients by ADIFOR Complex Analysis Code in FORTARN FORTRAN source code that can evaluate gradients Automated Differentiation Package Euler

43. February 7, 2002MDO - 42 Aero India 2003, Bangalore Design / MDO Studies @CASDE MDO Studies in formative stages  Hypersonic Vehicles - Integrated System Optimization (J Umakant)  Launch Vehicles - Reliability Based Design (Shyam Mohan)  Launch Vehicle – Simultaneous optimization of trajectory & system (Geethaikrishnan)

44. February 7, 2002MDO - 43 Aero India 2003, Bangalore Presentation made on behalf of CASDE PM Mujumdar, K Sudhakar Amitay Isaacs, SK Sane, AG Marathe VISIT http://www.casde.iitb.ac.in/ for information on MDO & Other activities