Kriging-Based Aeroelastic Gust Response Analysis at High Angles of Attack

Abstract

This paper presents a kriging-based methodology for analyzing aeroelastic gust responses at high angles of attack. Linear analysis becomes inaccurate due to the flow separation at such conditions, thus requiring computational fluid dynamics (CFD) simulations. However, the computational expense associated with CFD simulations renders them impractical for analyzing a large number of gust responses. Kriging interpolation is a computationally efficient alternative. In this study, it facilitated the analysis of 2584 one-minus-cosine gust cases with varying mean angles of attack, gust-induced angles of attack, and gust lengths, performed outside the CFD environment, with the help of just 36 CFD simulations. The accuracy of the kriging-based aeroelastic gust analyses was indicated by the extensive validations presented here, and its limitations are also discussed. The results show that, at high angles of attack leading to incipient stall conditions, nonlinear gust responses are relatively lower than their counterparts obtained via linear analysis. However, this drop in the relative response changes drastically with gust length, and this behavior is significantly enhanced with an increase in the angle of attack. This indicates the importance of extensive high-fidelity gust analysis at high angles of attack for structural design applications.