Wave properties and band gap analysis of deploying pipes conveying fluid with periodic varying parameters

Wave propagation and band gap (BG) characteristics of deploying long pipes conveying fluid are investigated based on a phononic crystal (PC) pipe model. The dispersion relation of the corresponding time-variant uniform pipe system is first derived in terms of the traveling wave feature of axially moving structures. Basic wave properties, such as the propagating and evanescent waves and the phase velocity and group velocity of propagating waves,...