Analysis of leaky guided waves propagating in a water-filled pipe

Cylindrical pipes are widely used in industries such as nuclear power plants and micro total analysis systems (μTAS). Nondestructive evaluation (NDE) of such pipes is therefore crucial. NDE as well as ultrasonic flowmeters can be used to characterize pipes filled with fluid. Guide wave of a hollow pipe was investigated theoretically by Gazis[1], and we previously expanded on the theory proposed by Gazis for a fluid-filled pipe[2]. We obtained an analytical result for guided waves that propagate in a cylindrical pipe, whose wave number was a complex number.[3] Pavlakovic theoretically investigated leaky guided waves propagating in a multilayer cylindrical pipe, and he chose the Hankel function for the liquid core[4]. However, Hankel functions are not suitable for the liquid core because they diverge at the center axis of the pipe. In this article, we analyzed the leaky guided waves propagating in a water-filled pipe, and discussed the effect of the attenuation of fluid.