The Application of Decomposition to the Large Scale Synthesis/Design Optimization of Aircraft Energy Systems

Authors : Jules MUÑOZ, Michael VON SPAKOVSKY

Pages : 61-76

View : 13 | Download : 6

Publication Date : 2001-06-01

Article Type : Research Paper

Abstract :An application of a decomposition approach for large-scale optimization insert ignore into journalissuearticles values(i.e., the Iterative Local-Global Optimization insert ignore into journalissuearticles values(ILGO); approach); developed by Muñoz and von Spakovsky insert ignore into journalissuearticles values(2001); is presented. The synthesis / design optimization of a turbofan engine coupled to an environmental control system for a military aircraft was carried out. The problem was solved for a given mission insert ignore into journalissuearticles values(i.e. a load / environmental profile); composed of fifteen segments. The number of decision insert ignore into journalissuearticles values(independent); variables both discrete and continuous for this highly non-linear optimization problem was one hundred fifty-three. Both the thermodynamic and physical insert ignore into journalissuearticles values(weight and volume); simulations were carried out using state-of-the art tools. Three objective functions were investigated: take-off gross weight, mission fuel consumption and total cost, and no observable differences were found in the final results. In addition to the mathematical foundations for global convergence presented in Muñoz and von Spakovsky insert ignore into journalissuearticles values(2000b, 2001);, convergence was validated numerically by solving the entire mixed-integer non-linear programming insert ignore into journalissuearticles values(MINLP); problem without decomposition using a subset of the independent variables. The constant value of the shadow prices insert ignore into journalissuearticles values(or linear behavior of the Optimum Response Surface – OSR); played a major role in global convergence of the ILGO approach.
Keywords : optimization, decomposition, aircraft synthesis design, multi disciplinary design optimization MDO, thermoeconomics