The Analysis of Thermomechanical Periodic Motions of a Drinking Bird

A water drinking bird or simply drinking bird (DB) is discussed in terms of a thermomechanical model. A mathematical expression of motion derived from the thermomechanical model of a drinking bird and numerical solutions are explicitly shown, which is helpful in understanding physical meanings and fundamental difference between mechanical and thermomechanical periodic motion. The mathematical and physical differences between mechanical and thermomechanical motions are clearly examined, resulting in time-independent and time-dependent coupling constants of equations of motion and continuous transitions between bifurcation solutions. The thermodynamical and irreversible process of a drinking bird motion could be theoretically examined and practically applied to energy harvesting technologies by way of the current modeling. As an example of irreversible thermodynamics, the thermomechanical model of DB will help understand heat engines manifested from microscopic to macroscopic systems.