This study presents numerical simulations of an ultrasonic waveguide sensor using the general-purpose simulation software COMSOL Multiphysics®. Ultrasonic sensors are widely used in various industrial fields due to their simplicity, low cost, and robust performance. In this study, a single cylindrical solid waveguide with multiple notches is used as a temperature sensor, enabling temperature measurement at multiple points using a single sound source. Though there are many wave modes in cylindrical waveguides, this study focuses only on the fundamental longitudinal mode. The aim of this work is to study the propagation of ultrasonic guided waves in the waveguide, their interaction with notches, and the time-of-flight (TOF) of the reflected signals at different temperatures.
Esmatullah et al. (Wed,) studied this question.