▎ 摘 要
In this paper, normal and tangential coefficients of restitution for gaseous molecules colliding with layerwise (single and few layers) graphene nanosheets were calculated using non-equilibrium molecular dynamics method. The normal and tangential coefficients of restitution depend on impact angle, velocity and landing position of projectiles. These parameters were evaluated computationally by implementation of several operations. Some differences were observed between proposed problem and macro-scale nature. The most notable difference was proportionality between the restitution coefficients and impact velocity, while in the case of macro-scale systems, they have inverse relation. Number of layers of graphene substrate does not contribute significantly to the normal and tangential coefficients of restitution. On the other hand, except for hydrogen, where its normal coefficient of restitution is approximately unity, the normal coefficient of restitution for other gasses increases as impact angle increases. Furthermore, tangential coefficients of restitution reduce with impact angle. These results can offer additional insights for further understanding the impact mechanisms and bombardment-related phenomena in low-dimensional materials. Presented results could be utilised to optimise some applied operations such as porosity generation via bombardment of layered nanostructures, gas detection process, thermal management and pressure sensor applications.