Piezoelectric material has been utilised to construct a small scale (μW order) power generator devices in recent years. In the case of aerial vehicles, some works have presented its implementation on small unmanned aerial vehicles (UAV). However, an application on larger aircraft structure has not yet been investigated. The present work aimed to seek insight into the potential energy that could be harvested from a large aircraft structure, i.e., wing. The alternative energy support may reduce fuel consumption and improve flight performance. However, the computational procedure fit for design purposes of an aircraft with energy harvesting capability also has not yet been developed. Thus, the development of computational methods for energy harvesting from an aircraft structure is also aimed in the present work.
As the first part of the present work, a novel hybrid mathematical/computational scheme is built to evaluate the energy harvested by a mechanical system. The governing voltage differential equations of the piezoelectric composite beam can be coupled with the output from a numerical method, e.g. the Finite Element Method (FEM). The scheme can evaluate various excitation forms concerning bending deformation including dynamic force and base excitation. In this report, the capabilities and robustness of the scheme are compared with results from the literature. Implementation to the
simulation of a notional jet aircraft wingbox with a piezoelectric skin layer is shown in some detail. The results pointed out that the electrical power generated can be as much as 39.13 kW for a 14.5 m wingspan.
The second part of the present work focused on the evaluation of alternative composite material, namely the multiphase composite with active structural fiber. The active structural fiber constructed of carbon fiber as a core with a piezoelectric shell as the coating can be flexibly optimised in terms of weight and electromechanical coupling. Hence, it may provide a lightweight benefit compared to the bulk piezoelectric material. In the present work, for the first time, the multiphase composite is implemented for energy harvesting purpose. An application to a notional jet aircraft wingbox is evaluated. An analysis of the trade-off between the energy harvested, the weight reduction and the fuel saving of the aircraft is shown in some detail.
Lastly, the third part of the present work is the development of a novel iterative FEM for piezoelectric energy harvesting. The application of the present iterative FEM to evaluate the piezoelectric energy harvesting of lifting structures under an aeroelastic
condition, i.e., gust load, is shown in some details. Furthermore, energy harvesting potential from a transport aircraft wingbox is also investigated. The results pointed out that the wingbox is still in a safe condition even when it is subjected to a 30 m/s gust amplitude while harvesting 51 kW power. In addition, for the first time, stress and failure analyses of the structure with an active energy harvesting layer are performed.
