Approach to Aerodynamic Design Through Numerical Optimization

A multipoint optimization approach is used to solve aerodynamic design problems encompassing a broad range of operating conditions in the objective function and constraints. The designer must specify the range of on-design operating conditions, the objective function to be minimized, a weighting function based on the mission or fleet requirements, and a set of performance and geometric constraints. Based on this designer input, a weighted-integral objective function is developed. The numerical optimization problem is then formulated as a constrained multipoint problem with the weight assigned to each operating condition determined by a quadrature rule. The approach is illustrated with several design problems for transonic civil transport aircraft and is extended to the formulation of aircraft range and endurance objective functions for use in the design of an unmanned aerial vehicle. The results demonstrate that the approach enables the designer to design an airfoil that is precisely tailored to the problem specification. Pareto fronts are presented as a means of providing the designer with information on tradeoffs that can be used to guide the problem specification.