GRADIENT-BASED AERODYNAMIC SHAPE OPTIMIZATION USING ALTERNATING DIRECTION IMPLICIT METHOD

A gradient-based shape optimization methodology that is intended for p ractical three-dimensional aerodynamic applications has been developed , It is based on the quasianalytical sensitivities. The flow analysis is rendered by a fully implicit, finite volume formulation of the Eule r equations. The aerodynamic sensitivity equation is soiled using the alternating direction implicit algorithm for memory efficiency, A flex ible wing geometry model that is based on surface parameterization and planform schedules is utilized. The present methodology and its compo nents have been tested, ia several comparisons. Initially, the flow an alysis for a wing is compared with those obtained using an unfactored, preconditioned conjugate gradient approach (PCG) and an extensively v alidated computational fluid dynamics code, Then, the sensitivities co mputed with the present method have been compared with those obtained using the finite difference and PCG approaches, Effects of grid refine ment and convergence tolerance on the analyses and the shape optimizat ion have been explored, Finally, the new procedure has been demonstrat ed in the design of a cranked arrow wing at Mach 2.4. Despite the expe cted increase in the computational time, the results indicate that sha pe optimization problems, which require large numbers of grid points, can be resolved with a gradient-based approach.