초음파 음장 가시화 연구의 과학 교수-학습에의 적용

Abstract

The purpose of this paper is application of study on ultrasonic acoustic field visualization to science instruction and learning. There are many methods of ultrasound acoustic field visualization. In this study, Fresnel and Schlieren methods were used for the frequencies of 700kHz, 1MHz, 2MHz, 2.25MHz and 2.5MHz. The standing wave patterns were obtained by the Fresnel method. The patterns showed parallel lines when one transducer operated in a water tank which had a reflector on its bottom. Lattice patterns were obtained when two transducers operated in orthogonal. The progressive and focusing wave patterns were obtained using the Schlieren method. The progressive wave patterns showed main lobe and side lobe. When a faulty transducer was operated, the schlieren image was different to normal transducer's one. The focusing wave patterns showed that ultrasound were focused at focal point. Although the constructed system is not enough to obtain clear images due to misalignment and poor optical devices. If the system is improved, it will be very useful to understand the phenomena of acoustic wave propagation, and it will become one of powerful tools to teach waves propagation phenomenon to students in the school and to test ultrasonic transducers in industries.