Energy harvesting from thermally induced vibrations of antenna panels

Though vibration energy harvesting technology has been extensively explored in the past decades, harnessing energy from thermally induced vibration has been rarely investigated. This study, for the first time, proposes a piezoelectric energy harvester (PEH) excited by time-varying thermal loading in outer space to power wireless electronics in antenna panels of satellites. A novel thermal-mechanical-electrical coupling model is developed to accurately predict the dynamic response of the system. Firstly, based on the comprehensive analysis of spatial heat fluxes, the transient thermal conduction equations are derived via the variational principle. Subsequently, different from conventional incremental finite elements, the thermoelasticity of the panel is characterized by the absolute nodal formulation. Taking advantage of invariant matrices, an enhanced mathematical model is constructed to improve the computational efficiency of the thermoelastic forces and their Jacobian matrices. Furthermore, an electromechanically-coupled analytical model is put forward for the PEH installed on the antenna panel. Finally, an integrated computational framework is established to iteratively solve the multi-physics coupled problem with second-order accuracy. A corresponding finite element model is also built for verification. The effectiveness and efficiency of the developed multi-physics model are demonstrated through a comparison with the simulation results. In particular, the proposed analytical model not only considers the bidirectional interaction between the elastic deformation and heat absorption, but also incorporates the coupling relationship between the piezoelectric effect and structural vibration. Moreover, the investigation results provide pivotal insights into the design of the energy harvesting system excited by thermally induced vibration.