On a method for vibration analysis of viscous compressible fluid-structure systems

A fluid-structure interaction formulation for viscous compressible fluid is under consideration. The formulation involves finite element approximation of linearized Navier-Stokes equations and response determination made by means of modal superposition analysis. Standard and simplified schemes of the viscous compressible fluid-structure interaction problem solution are developed. The schemes are based on the frequency condensation method of a complex eigenvalue problem solving. Free and forced oscillations of several fluid-structure systems are studied by the standard and simplified schemes. The analysis of the results obtained shows that the simplified scheme provides a saving of 90% of the computational time required to define oscillation of the structure with viscous compressible fluid in the lowest frequency range. A certain influence of the fluid viscosity on the transient response of the fluid-structure system is also demonstrated. Copyright (C) 2004 John Wiley Sons, Ltd.