Theoretical modelling and nonlinear analysis of galloping flexoelectric energy harvesters with blunt bodies of different sizes

Abstract

This study evaluated the behaviour of a novel galloping energy collector based on the flexoelectric effect, for which the dynamic equation governing the energy conversion system is established by applying Hamilton’s principle. The aerodynamic coefficient curve for the blunt body, characterised by width-to-thickness ratios ranging from 1.0 to 2.0, is analysed for various wind angles using the simulation software. The galloping response characteristics of the system and its energy export performance for varying parameters are investigated using numerical simulation. The findings reveal that the number of inflection points in the aerodynamic fitting curves varies across diverse width-to-thickness ratios, resulting in three forms of dynamic responses. This variation significantly impacts energy harvesting. Furthermore, the results demonstrate that for wind speeds (U) from 1 to 3 \({\text{m}}/{\text{s}}\), the optimal width-to-thickness ratios for the blunt body fall between 1.5 and 2.0. When U exceeds 3 \({\text{m}}/{\text{s}}\), the appropriate width-to-thickness ratio falls within the range of 1.0–1.5. The influence of resistance on the electrical export of the system is also discussed, and the best matching resistance is determined so that the geometrical parameters and the resistance can be designed to realise the optimal regulation of the system’s amplitude, onset wind speed of the galloping dynamic and the electrical export.