ESTIMATION OF THE LOSSES OF ENERGY OF ACOUSTIC VIBRATIONS IN THE COURSE OF ULTRASONIC TESTING IN THE ATMOSPHERE OF NATURAL GAS

摘要

We propose a method for the evaluation of the losses of ultrasound vibrations in the course of contact-less ultrasonic testing in an atmosphere of natural gas taking into account the physical and geometric parameters of the medium of propagation of ultrasound and tested objects for the choice of the materials of piezoelectric transducers and matching layers. This method enables us to estimate the influence of the physical parameters of the medium and tested object (temperature, pressure, composition, material, and thickness) on the losses of ultrasonic signals for the choice of their optimal values. The losses of ultrasonic signals are estimated for the case of unilateral monitoring of the thickness of the wall in a pipeline aimed at the transportation of natural gas with given composition under pressure. The results of our analyses make it possible to conclude that, in the case of application of matching layers chosen with regard for the parameters of the medium and contemporary algorithms for processing of the data of measurements, it becomes possible to realize flaw detection and monitor the thickness of the main pipeline in an atmosphere of natural gas under the action of working pressure.