Modelling the ultrasonic field generated by mono and multi element transducers through interfaces

This paper presents a computational method for determining the reflection and transmission of ultrasonic beams through plane interfaces between elastic media radiated from mono and multi element transducers. The ultrasonic field is calculated by the Rayleigh integral method, which is affected by reflection and/or transmission coefficients. In a first step, the velocity potential impulse response is calculated at the interface. In a second step, the reflected and transmitted pressure field is calculated by applying the Huygens' principle to the whole-extended interface. The method is valid for all field regions, may be performed for any excitation form, and can be easily applied in the case of arrays. In order to validate the method, the simulated field from a single piston-like transducer is compared to an experimentally measured field considering the wave evolution caused by planar interfaces between two media (water-acrylic). Finally, computation examples using phased arrays are also shown in the paper.