Modeling and characteristic analysis of gas–aluminum triboelectric charging mechanisms

Abstract Gas–solid friction can induce interfacial charge transfer, and the harvested triboelectric charges can, in principle, power distributed sensor networks on aircraft surfaces. However, the charging behavior of gas–solid triboelectrification under varying flight conditions remains insufficiently investigated. In this study, a theoretical estimation model for gas–solid triboelectric charging on moving surfaces is developed, and its key influencing factors are analyzed. Based on the Maxwell–Boltzmann velocity distribution, the model demonstrates that, under constant ambient temperature, the generated charge is jointly governed by the collision frequency between gas molecules and the solid surface and by the effective frictional area. The collision frequency, in turn, depends on the object’s velocity and the ambient pressure. A fluid–solid coupled simulation conducted in ANSYS Workbench provides preliminary verification of the model’s validity. Additionally, first-principles calculations confirmed that aluminum tends to lose electrons, exhibiting a positive charge during gas–solid triboelectric charging. Furthermore, a non-contact experimental system employing double through-type Faraday cups is designed to measure the charge-transfer efficiency predicted by the Maxwell–Boltzmann-based estimation under controlled variations in motion velocity, effective friction area, and ambient pressure. The experimental results confirm the correctness of the proposed estimation model. This work provides a theoretical foundation for analyzing the feasibility of powering distributed sensors on aircraft skins through gas–solid triboelectric charging.