Temperature influence on guided waves in a liquid-filled pipe

The varying temperature of liquid sodium is a vital factor affecting the development of a non-destructive evaluation (NDE) ultrasonic technique for health monitoring of sodium-cooled fast reactor (SFR). The main pipe of the secondary loop of SFR is a waveguide in which numerous guided modes exhibit. In this paper, temperature influence on dispersion characteristics of guided waves in a liquid sodium filled pipe model is investigated. It is analyzed that mode coupling between guided modes in a liquid cylinder and in a hollow pipe yields guided modes in a pipe filled with liquid. The aim is to select promising guided modes and suitable excitation frequency ranges, which are non-sensitive to the sodium temperature, low dispersion, and group velocity distinguishable, for NDE application.