Minimum-State Unsteady Aerodynamics for Aeroservoelastic Configuration Shape Optimization of Flight Vehicles

摘要

The minimum-state technique for creating linear-time-invariant state-space models of unsteady aerodynamic loads leads to major savings in terms of the dimension of the resulting aeroservoelastic systems compared to alternative techniques. The up-front effort of the generation of minimum-state approximants, however, is large and involves an iterative double least-squares function fitting process. When the overall shape of a configuration varies during the repetitive analysis required for configuration design optimization, the cost of creating new minimum-state approximations becomes prohibitive. This paper presents an efficient method for obtaining shape sensitivity analysis of minimum-state approximants. The resulting sensitivities are then used, based on a single detailed analysis and sensitivity analysis at some reference design to generate approximate aeroelastic poles, divergence speed, and flutter speed results for configurations that are subject to considerable planform shape changes.