Pressure-induced instability and its coupled aeroelasticity of inflated pillow

Abstract A floating air weapon system (such as airborne floating mines) plays an important role in modern air defense operations. This paper focuses on aerodynamic characteristics of airborne floating mine named inflated pillow. Firstly, the dynamic deployable process of the pillow and characteristics of the local instability of the edge are studied, and the evolution mechanism of wrinkles and kinks is analyzed. Secondly, in the cruising stage, the fluid-structural-thermal coupling analysis is performed on the pillow, and the aerodynamic characteristics are studied. Thirdly, the shape-preserving effect of the inflated pillow during the “negative pressure” slow landing stage is evaluated. It is found that when the wind velocity is higher, the pillow has a collapsed instability (surface extrusion and contact), and when the wind velocity is lower, snap-through instability occurs. Finally, for the collapsed instability, a carbon fiber skeleton is added to discrete the large global collapsed fold into small local folds, thus achieving shape-preserving effect of pillow. For snap-through instability, the critical internal pressure and different shape evolution under different wind velocity are evaluated. Through the analysis of the mechanical mechanism and control of the structural morphological evolution, it provides theoretical guidance for the application of the curved shell structure in floating air weapon system.