A numerical study of the effect of fluid-structure interaction on transient natural convection in an air-filled square cavity

The present study aims to investigate the transient natural convection in an air-filled square cavity based on the effects of fluid-structure interaction (FSI). The Prandtl number of air is assumed to be 0.71. A thin deformable baffle is horizontally located in the center of the cavity and the top wall of the cavity is also elastic. The horizontal walls are completely insulated. Initially, the cavity is set at Tc temperature, then the left side wall temperature is raised to Th. The arbitrary Lagrangian-Eulerian approach is implemented to study the flow field in the presented model. The fluid field equations are discretized by Galerkin finite element method. Further, the dimensionless equations of flexible parts of the cavity are solved using the Newton-Raphson method. The study examines the effects of Rayleigh number and baffle length on flow and temperature fields, heat transfer rate and deformation of elastic parts of the cavity. The results show that an increase in the Rayleigh number enhances the natural convection and increases the elastic parts deformations. Finally, the increase of baffle length has different effects on thermal performance of cavity depending on the Rayleigh number and rigidness or flexibility of the system.