Analysis of Focusing Performance in Phased Array Probe Using COMSOL

Abstract

To improve the detection ability of ultrasonic phased array detection for hydrogen storage vessel, COMSOL was used to simulate the main parameters of phased array probes. The influence of the number of array elements, array element spacing and excitation frequency on the sound propagation characteristics was analysed. The results showed that the number of array elements has a significant effect on the focused sound field. When the number of array elements is 8, effective focus cannot be formed at the pre-set focus position, and the maximum sound pressure value does not change significantly at the three pre-set focus depths. At a focus depth of 30mm, the maximum sound pressure in the 32-element mode is more than twice that in the 8-element mode. The relationship between excitation frequency and focal sound pressure is non-linear. In addition, as the array element spacing increases, the length of the focal column decreases. And the smaller the array element spacing, the higher the sound pressure at a deeper depth.

Numerical analysis of the phased array imaging with a stacked plate buffer

“…The beam forming and focusing are possible by adjusting the delay given to the vibrating elements, and new technologies have also been developed, such as a full matrix capture (FMC), which collects a very large number of waveforms by switching the vibrating elements, and a total focusing method (TFM), which is the imaging algorithm using the large number of waveforms collected by the FMC. [14][15][16][17][18][19][20][21][22] However, when considering the installation of a phased array probe in plant piping to monitor crack propagation during operation, the high temperature resistance of the phased array probes becomes important when the piping is subjected to high temperatures. For example, in new nuclear power plants that use liquid sodium as a coolant, the temperature of the piping can reach several hundred degrees Celsius, while a typical phased array probe can only maintain its functionality up to about 60 °C.…”