Sloshing ROMs for fluid-structure interactions in aerospace applications

This paper proposes Reduced-Order Models (ROMs) based on data provided by CFD codes, for the study of sloshing-integrated systems including the effects of the tank flexibility. A commercial CFD code addressed to sloshing analyses is employed to generate data set to be used for the ROM synthesis. The developed sloshing ROM, based on a Linearized Frequency Domain (LFD) approach, uses an Input/Output system identification technique from CFD transient simulations to construct an unsteady Generalized Sloshing Force (GSF) transfer function matrix in analogy with the Generalized Aerodynamic Force (GAF) matrix used to model the aircraft external unsteady aerodynamics for dynamic aeroelastic analyses. The obtained transfer function data are suitably fitted via rational polynomial form in the frequency sub-domain so achieving a state-space form for the sloshing ROM. The obtained finite state reduction has been suitable developed for applying it in aeronautical and space applications for perspective integrated (stability and response) analyses and design.