Wave Analysis Of Fluid-conveying CNTs With Surface And Nonlocal Effect

The physical characteristics of nanostructure has become a hot topic nowadays.There are three methods which are widely used including experiments,molecular dynamics simulation and continuum theory.Nanostructure is too small to be manipulated.Molecular dynamic simulation costs much time and money.Thus,the approach used most widely is continuum theory.Nowadays,classical continuum theory has been developed into nonlocal continuum theory with small scale effect considered.In practical application,nanodevices are usually used in multi-physical fields including temperature and magnetic fields.It’s meaningful to study the effect of multi-physical fields on wave through single-walled carbon nanotubes.Carbon nanotubes can be applied in transporting fluid and that makes it necessary to investigate fluid-conveying carbon nanotubes.In addition,carbon nanotubes have large specific surface area.Therefore,its surface effect can’t be neglected when investigating its physical behaviors.With all the factors mentioned above considered,the model of wave propagation through single-walled carbon nanotubes is established based on the combination of higher-order nonlocal strain gradient theory and Timoshenko beam theory.By comparing several order nonlocal strain gradient theories and the classical continuum theory,the nonlocal effect on wave characteristics is studied which can be seen from the wave curve.The effect of external environment factors,such as temperature change,longitudinal magnetic field and surrounding medium,on the wave propagation is also investigated.By utilizing Navier-Stokes theory,the force of inner viscous nano-flow on the tubes can be obtained.Then,applying this force into Hamilton’s principle,the motion equation can be written.The effect of surface elastic modulus,surface residual tension and surface density on the wave is also studied by using Gurtin-Murdoch surface elastic theory and nonlocal elastic theory.