Acoustic Signal Analysis for the Blockage Detection of Fluid-Filled Pipeline

In this paper, a wave propagation model is developed toinvestigate the wave propagation in a fluid-filled pipeline system. The dispersion characteristics of acoustic waves in a fluid-filled thick cylindrical shellare studied by using a multi-layer technique on thethree-dimensional shell equations. From this, theinfluence of many parameters, such as number of layers,on the wavenumber is obtained. The accuracy of the present model is found to be substantially better thanthe two-dimensional thin shell theory, but at theexpense of computational efficiency. Tests areconducted for the pipeline blockage detection using anactive acoustic pulse source. Several modes are excitedinside the coupling system and the position of the blockage can be detected from the reflection signal of the blockage along with advanced signal processingmethods. In particular, Smoothed Pseudo Wigner-VilleDistribution (SPWVD) has been used to extract thetemporal and frequency characteristics of the propagating waves from the measured signals.Experimental results demonstrate that SPWVD areeffective in detecting the position of the blockage.