Viscosity evaluation using transmitted ultrasonic pulse

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K14617
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Dynamics/Control
• Research Institution: Kyushu University
• Principal Investigator: Kadowaki Ren 九州大学, 工学研究院, 助教 (10735872)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 粘度測定 / せん断粘度 / 体積粘度 / 超音波パルス

Outline of Final Research Achievements

The purpose of this study is to measure flowability and adherability of viscus materials using a broadband ultrasonic pulse. Evaluation of the viscosity is the basic problem. We obtained an index for shear viscosity through a numerical simulation of a lumped model of the liquid and an experiment. And a damping coefficient of the connecting damper, which had not been considered meaningful for our previous viscosity identification, indicated a relationship with the shear viscosity and the bulk viscosity. Also this damping coefficient is effective to evaluate the viscosities. Experimental system was also improved so that the lower viscosity liquid than the previously used liquids was measured. This improvement broadened the range of application of our proposed evaluation method.

Free Research Field

機械力学

Academic Significance and Societal Importance of the Research Achievements

従来の粘度評価手法は液体が用いられているシステムから少量をサンプルとして取り出す必要があったため，当該システム内での液体の物性を測定できなかった．また，代表的なB型粘度計や振動式粘度計ではせん断粘度を測定できるのみで，体積粘度に関わる指標は得られなかった．本研究の成果は容器や管路の内部にある液体の粘度評価に有効で，体積粘度の評価にもつながる．特に，高温，高圧の環境で用いられる液体の流動性を評価する上で重要な知見であると考えられる．