Chaos in embedded fluid-conveying single-walled carbon nanotube under transverse harmonic load series

Stability and precision are important characteristics of the nanosyringe, a typical targeted drug delivery device. These characteristics of the nanosyringe are affected by the oscillating properties, especially by the chaotic behaviour resulting from the fluid–structure interaction effect of the fluid-conveying carbon nanotube. In this paper, the chaos in an embedded fluid-conveying single-walled carbon nanotube under transverse harmonic load series is investigated by the generalized multi-symplectic method which has been proved to be an accurate, efficient and long-time integration of infinite-dimensional nonconservative Hamiltonian systems. Considering the geometrical nonlinearity, the elastic medium restraint, the transverse harmonic load series as well as the fluid-conveying, the transverse oscillating model of the nanotube is presented firstly. And then, a generalized multi-symplectic scheme is constructed for the oscillating model to simulating the transverse oscillation of the nanotube. In the numerical experiments on the chaos in the nanotube, the following factors are considered: the length of the nanotube, the amplitude and the number of the transverse load series, the frequency and the initial phase of the transverse load series. From the numerical results, it can be found that, with the increase in the length of the nanotube and the increase in the number of the transverse load series, the chaotic region respected to the flow velocity decreases obviously, which implies that the stability and the precision of the nanotube are improved. These conclusions give some advice on the design of the nanosyringe, and the way that improves the stability and the precision of the nanosyringe in the process of work.