Constraint Analysis and Initial Sizing of a Transport Aircraft by Simulated Annealing

This paper discusses a novel approach to the initial sizing process in aircraft conceptual design. In the classical approach, the design point is obtained either graphically or by simultaneous solution of the constraint equations. In this approach, the design point is obtained by coupling the constraint analysis and Sizing procedure to an optimization algorithm, and then arriving at the optimum value of an objective function, subject to the constraints. As an example, the initial sizing of a jet-engined transport aircraft is carried out by coupling Loftin s constraint analysis and sizing procedure for minimum take-off weight to SIMANN Simulated Annealing optimization algorithm. The wing loading and power loading for minimum take-off weight obtained by this approach compare very well with the values obtained using the graphical approach. The results obtained by applying this method for constraint analysis and sizing for the two other objective functions are also presented.