Image reconstruction of blockage in the continous and stepped pipelines by noninvasice acoustic method

Abstract

The image of a semi-circular blockage and location in the uniform and stepped pipe was reconstructed by measuring the eigen-frequency shift of the resonance and anti-resonance frequencies of multi-sine acoustic waves. In this study we have used different boundary conditions from previous works of Wu and Fricke [1] and De Salis and Oldham [2] to determine the blockage cross-sectional area and position. The results agreed with real fractional cross sectional area and position in the both continuous and stepped pipes. New approach showed a better quality of reconstructed image with small ripple number and the false dummy blockage signal was also reduced. The present method of blockage image reconstruction is a noninvasive nondestructive and can meet the integrity evaluation implementation for all types of transmission pipeline.