Vibration and instability of carbon nanotubes conveying fluid

Carbon nanotubes may find significant application in nanotechnology as nanopipes conveying fluid. This paper studies the influence of internal moving fluid on free vibration and flow-induced structural instability of carbon nanotubes. Detailed results are demonstrated for the dependence of resonant frequencies on the flow velocity, and the critical flow velocity at which structural instability of carbon nanotubes emerges is calculated. The results indicate that internal moving fluid could substantially affect resonant frequencies especially for suspended longer carbon nanotubes of larger innermost radius at higher flow velocity, and the critical flow velocity for structural instability in some cases could fall within the range of practical significance. On the other hand, even a compliant surrounding elastic medium (such as polymer matrix) can significantly reduce the effect of internal moving fluid on resonant frequencies, and suppress or eliminate structural instability within the practical range of flow velocity.