Propagation of thermal waves across a wedge

Abstract

Photothermal techniques have been widely developed to study the thermal properties and to detect buried defects of samples with flat parallel surfaces. In the last years, there has been a growing interest in the application of photothermal techniques to samples with non-flat surfaces, as is the case of rods, tubes, and balls. The aim of the present work is to study the propagation of thermal waves across wedge samples. We have considered plane illumination (launching plane thermal waves) as well as Gaussian illumination (producing spherical thermal waves). We focus on the behavior of the front and rear surface temperatures, which is recorded using lock-in infrared thermography. This work is aimed at expanding the use of photothermal techniques for the quantitative characterization of wedge samples, as is the case of gear, blades, screws, and other hardware tools.