Efficient aeroelastic analysis of wind loads on inflatable hangars

Abstract

Wind loads play a crucial role in inflatable structures. Unfortunately, design loads from safety regulations grossly overestimate the real aerodynamic forces. Thus, a more accurate estimation of wind loads is desirable. Conventional CFD approaches (e.g. LES) struggle with the complexities of the flow field (intricate geometry and massive flow separation) and require a very high computational effort. We present a cost-efficient tool for the aeroelastic analysis of inflatable hangars. It uses a staggered solution scheme with an explicit finite-element structural solver and potential flow aerodynamics. To account for large areas of separated flow typical of blunt shapes, a semi-empirical correction is applied to the inviscid solution. The streamlines of the potential solution are computed and, for each one, the separation point is predicted with Stratford’s criterion. Finally, an empirical correction is applied to the inviscid pressure field. We present validation benchmarks as well as a real life application example. Over the majority of the flow field, the pressure field agrees well with high-fidelity computations, yielding similar global loads for structural sizing. This is achieved with a small fraction of the computational effort required by conventional CFD approaches.