Wave propagation characteristics in fluid-conveying double-walled nanotubes with scale effects

In this paper, the propagation characteristics of the elastic wave in fluid-conveying double-walled carbon nanotubes are investigated. The nonlocal continuum theory is applied to discuss the dispersion relation with small scale effects. The interaction of the double tubes is considered with the van der Waals interaction pressure and the equation of the flexural wave for the double-walled Euler–Bernoulli beam model is derived. The properties of the frequency and the amplitude ratio are proposed with different wave numbers and fluid velocities. From this work, it can be observed that the small scale effects should be considered in the investigation of the elastic wave propagation in fluid-conveying double-walled nanotubes.