Isentropic wave propagation in a viscous fluid moving along a lined duct with shear flow and its implication for ultrasonic flow measurement

Present paper investigates the influences of the fluid viscosity and acoustic impedance of the wall on the isentropic acoustic wave propagating along a shear flow contained in a circular pipeline. On the assumption of an axisymmetric acoustic wave, mathematical formulation with respect to the acoustic velocity is deduced from the conservation of mass and momentum. Numerical calculation is processed through an iterative procedure based on the Fourier–Bessel theory. Comparisons of the wave attenuation and measurement performance of an ultrasonic flow meter are addressed among the rigid, steel and aluminum walls. Meanwhile, the differences between the laminar and turbulent flow are provided. In conclusion, parametric analyses of the influence of the acoustic impedance on the wave attenuation and ultrasonic measurement performance are given.