The fluid structure interaction effect on the vibration and instability of a conveyed double-walled boron intride nanotube

The eect of Knudsen number (Kn) on the nonlinear vibration and instability of double-walled boron nitride nanotubes (DWBNNTs) conveying uid has been investigated, based on Fluid Structure Interaction (FSI). The embedded DWBNNT is simulated as a Timoshenko Beam (TB), which includes rotary inertia and transverse shear deformation. The electro-mechanical governing equations are derived using the nonlocal piezoelectricity theory and discretized by a Dierential Quadrature Method (DQM). Regarding the types of ow regime in FSI, including continuum, slip, transition and free molecular, the value of Knudsen number as a small size parameter is designated and utilized to modify the uid velocity. Considering the slip condition for an internal nanotube, the eects of Knudsen number on various vibration modes, small scale, and nonlinear frequency amplitude are also taken into account for a clamped-clamped boundary condition. Results indicate that, based on the slip ow regime, the Knudsen number is an important parameter in FSI that changes the critical ow velocity and instability of nano systems and, therefore, should be considered in nanotubes conveying uid.