Multidisciplinary Aspects of Design System Level Optimization Emphasis is on the multidisciplinary nature of the Why system-level,multidisciplinary optimization complex engineering systems design process.Aero- space vehicles are a particular class of such systems Disciplinary specialists tend to strive towards improvement of objectives and satisfaction of constraints in terms of the variables of their own discipline Structures Control Emphasis in recent years has In doing so they generate side effects-often unknowingly- been on advances that can that other disciplines have to absorb,usually to the Aerodynamics be achieved due to the inter- action of two or more detriment of the overall system performance disciplines. System Engineering by J.J.Gao ③cLao System Engineering by J.J.Gao ③cLco 6 Aircraft "Optimization" System Level Optimization Breguet Marketing Aero Range D Equation AI→ R- V(L/D). Vwie AR &·SFC Marketing:maximize Aero:maximize L/D passenger volume Cabin diameter →Aspect Ratio Propulsion Structures M R=Range [m] V=Flight velocity [m/s] SFC Specific Fuel Consumption [kg/s/N] L/D Lift-over-Drag ration [N/N] BPR- g gravitational acceleration [m/s?] Structures:minimize Propulsion:minimize Win=Initial (takeoff)weight [N] structural mass specific fuel consumption W=Weight at end of flight [N] (sFC)→Bypass Ratio Wie=Winbar-Wina Fuel quantity [N] →Wing-root moment System Engineering by .Gao ③ctoo System Engineering by .J.Gao ⑦ctGe 8+ - System Engineering by J. J. Gao 5 Multidisciplinary Aspects of Design + - System Engineering by J. J. Gao 6 System Level Optimization + - System Engineering by J. J. Gao 7 Aircraft “Optimization” + - System Engineering by J. J. Gao 8 System Level Optimization