Effect of Plate Attachment Location on the Dynamics of a Flexible Cantilever in a Thermally Driven Square Cavity.

The fluid-structure interaction (FSI) dynamics of flexible structures in thermally driven environments are critical for understanding heat transfer enhancement, energy harvesting, and biological flow systems. In this study, we numerically investigate the behavior of an elastic cantilever plate placed within a square cavity subjected to convection. The plate is attached to different cavity walls, namely, the left and right adiabatic walls and the bottom hot wall, to analyze how its placement affects the coupled flow-structure dynamics. An open-source multiphysics solver, SU2, is used to simulate the motion of the flexible plate and the surrounding buoyancy-driven flow. Time-resolved responses, phase portraits, and power spectral densities are computed to characterize the steady, periodic, and chaotic regimes observed in the system. Bifurcation analysis is employed to systematically explore the transitions in the dynamic behavior of the plate as a function of key non-dimensional parameters, such as Rayleigh number, Cauchy number, and plate location. The results reveal that the location of the plate significantly influences the onset of oscillations, vortex-structure interaction patterns, and thermal transport characteristics. Particularly, plates attached to the hot bottom wall exhibit distinct instability routes compared to those mounted on adiabatic sidewalls. This study provides new insights into the role of geometric and thermal boundary conditions in shaping the nonlinear dynamics of flexible structures in convective enclosures, with implications for the design of thermal management systems and flow control devices.