Propagation of monopole source excited acoustic waves in a cylindrical high-density polyethylene pipeline

Abstract

Acoustic wave propagation (up to 50 kHz) within a water-filled high-density polyethylene (HDPE) pipeline is studied using laboratory experiments and theoretical analysis. Experiments were carried out in a 15 m length of cylindrical HDPE pipeline using acoustic transducers to acquire signals uniformly spaced along the axis of the pipe. By proposing the use of the iterative quadratic maximum likelihood algorithm to this experimental configuration, wavenumbers, attenuations, and mode amplitudes could be accurately extracted from the measurement data. To allow comparisons with theoretical analysis, dispersion curves of the wavenumbers, attenuations, and acoustic power characteristics of the axisymmetric and nonaxisymmetric modes are predicted by extending an existing waveguide model. The model extensions included the introduction of a monopole acoustic source into the water medium so that amplitude variations with respect to individual modes and frequencies could be investigated in detail. In addition, stiffness coefficients of HDPE material are carefully used to account for viscoelastic effects. The comparisons between the theoretical predictions and experimental results demonstrate a very good match and are a validation of the theoretical model.

Laboratory and field experiment validations on the use of hydraulic transients for estimating buried water pipeline deterioration

“…Equation (1) is derived using the mass balance relation in a fully water-filled flexible pipeline. 23 It only accounts for the fundamental mode, rather than the higher-order modes with cut-off frequencies, 24,25 but it is well suited to the low frequency fluid transients used for pipe inspection. It is also worth noting that finely distributed air can result in a dramatic reduction of wave speed and occurs in close proximity of hydromachinery or piping that has recently undergone repairs.…”

Analytical Solution for the Propagation of Guided Acoustic Waves in Multilayered Cylinders Applied to Through-Tubing Cement Bond Logging in Oil Wells

“…Similar to the previous case, Li et al [76] also proposes the analytical solution for a case involving a single cylindrical layer, however composed by a high-density polyethylene (HDPE). Furthermore, in this case water is used as the inner medium.…”

“…Figure 5.4 -(a) Phase velocity by frequency obtained by the analytical model proposed in this work. The colored curves represent the bulk waves velocities in each media presented in this configuration (b) Phase velocity by frequency used to validate the analytical model presented in[76] …”