The characteristic analysis of Phase-controlled array thermo-acoustic emission with multiple emitting surfaces

Abstract

Abstract Thermo-acoustic(TA) ultrasound has generated lots of interest during the last decade for its many advantages, especially combined with the phased-controlled array technology. In this paper, a theoretical expression about the TA phased array(TAPA) emission was established to study the different acoustic field based on the input heat flow frequencies, number, distances, area of TA emission surfaces, and phase change between emission surfaces. It is found that, the two emitting surfaces in a line pattern TAPA has the consist acoustic field with the single emitting surface in the semicircle. Meanwhile, applying different phases on the surface ,the scanning range will be narrowed by the increase of frequency, the area of the TA emission surface and the number of emission surfaces, but accordingly, the directivity of the TA wave will be enhanced. The increase of the distance between the emitting surfaces of the TAPA arranged in a cross shape does not affect the ultrasound pressure of the main TA ultrasound, but only increase the number and size of the side flaps; The increase of the area of the emitting surfaces will make the TA ultrasound increase in directivity, so the TAPA in a cross shape must reduce the distance of emitting surfaces to enhance the directivity, or increase the area of the emitting surfaces. This paper proposes a comprehensive study of the TAPA to help further research in the TAPA field.