Multiphysics model reduction of symmetric vibro-acoustic formulation with a priori error estimation criteria

A new multiphysics mode synthesis (MMS) is presented for the construction of reduced-order models of acoustic fluid-structure interaction systems. The present acoustic-structure interaction model is symmetric and consists of the fluid pressure p, the fluid displacement potential φ, and the structural displacement u. In carrying out MMS, the structure is first reduced, which is then applied to the coupling terms in the acoustic (p, φ)-equations. The fluid parts (p, φ) are then reduced while preserving the coupling effects, resulting in improved accuracy. A combination of a priori modal contribution indicator and cumulative error estimator are derived from the moment matching approach that provides rational criteria for how many structural and fluid modes need to be retained for the construction of reduced models. An iterative MMS algorithm is then proposed by combining the modal indicators and error estimators. The performance of the proposed MMS method is illustrated via numerical examples.