Development of ultrasonic probe evaluation system using change in liquid surface shape due to acoustic radiation pressure

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K04253
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 20010:Mechanics and mechatronics-related
• Research Institution: The University of Electro-Communications
• Principal Investigator: Nomura Hideyuki 電気通信大学, 大学院情報理工学研究科, 教授 (90334763)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 音響放射圧 / 音響流 / 音響パワー / 音圧 / 超音波プローブ

Outline of Final Research Achievements

To establish a new evaluation method for ultrasonic probes, we proposed and evaluated a method based on the measurement of water surface shape change by acoustic radiation pressure.
First, a theoretical model that takes into account the large-amplitude of water surface displacement was developed and compared with measurements. The results were not sufficient to explain the water surface displacement proportional to the cube of the sound pressure as shown in the measurement results. Next, instead of an unstable water surface, a thin film was used to measure the displacement due to radiation pressure, and its stability was verified. Finally, radiant power was measured from the obtained water surface displacement. The results showed larger values than those estimated by the hydrophone method.
Further studies on the relationship between water surface displacement and sound pressure and more accurate measurement methods are needed.

Free Research Field

音響エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

放射圧による水面変位計測によって音響パワーと放射圧分布の同時計測が可能となる点が，社会的に意義ある成果である．この手法が確立されることで，現場における超音波プローブの評価が容易になる．
音響パワーに比例する放射圧が，今回の研究では示されなかった．このことは今後解決する必要があるが，同時に新たな物理メカニズムが潜んでいる可能性を示唆している．したがって，この現象の追求は新たな超音波現象の発見につながる可能性がある点で，学術的意義を有する．