A strongly coupled model reduction of vibro-acoustic interaction

This paper presents a new formulation of the coupled reduced-order modeling technique for fluid–structure interaction problems. The problem addressed here is a classical vibro-acoustic issue, which is a coupled vibration of an acoustic fluid in an elastic structure. Discretization of the problem yields a model having many degrees of freedom, which may impede rapid simulation and analysis. Projection-based model reduction is thus the most popular way to handle this problem. Conventionally, structure and fluid modes are independently employed to reduce their own degrees of freedom, and the Schur complement is then used to make a weak coupling between the two domains. In this work, we suggest a new coupled formulation to build a strong connection between the fluid and structure, which is mathematically a sequential projection from structure to fluid. The proposed strongly coupled formulation provides insight into the way that the structural vibration energy is transmitted to the fluid domain. Consequently, it can offer more precise reduced-order modeling of the fluid–structure interaction problems than conventional approaches. Numerical results herein demonstrate improved accuracy of the proposed method. •We propose a strongly coupled model reduction of vibro-acoustic interaction.•Fluid–structure mode synthesis is a key idea for the precise model reduction.•Theoretical and numerical investigations were conducted to compare the proposed and conventional methods.•The performance of the proposed method was demonstrated through the numerical examples.