CFD-Based Gust Response Analysis of Free Elastic Aircraft

The study presents two novel approaches for gust response analysis of elastic free aircraft configuration using computational fluid dynamics (CFD) tools. The direct approach involves full aeroelastic dynamic simulation within a CFD run. The hybrid approach involves computing rigid sharp-edge gust responses in a CFD run, evaluating the gust input forces due to arbitrary gust profiles via convolution using those rigid sharp-edge gust responses, and applying a linear aeroelastic feedback loop. The latter is highly computationally efficient, as only one relatively short CFD run is required for the computation of the sharp-edge gust responses, after which responses to arbitrary gust profiles can be computed in seconds. The former is more elaborate and time consuming, and can be used in cases in which the elastic response may be non-linear. The two methods are demonstrated by computing responses to one-minus-cosine gust inputs of a transport aircraft model.