Construction of lattice-Boltzmann method for direct simulation of the interaction between a gas-liquid interface and sound

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K03930
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Kobe University
• Principal Investigator: Kataoka Takeshi 神戸大学, 工学研究科, 准教授 (20273758)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 流体音 / 気液界面 / 数値計算法

Outline of Final Research Achievements

We have developed a two-dimensional LBM model that can simulate interaction of a water droplet with sound by introducing two different kinds of particles for the liquid and gaseous phases. The most striking difference between the liquid and gaseous phases is their density and compressibility, and their differences are modeled by the use of appropriate intermolecular forces. With these modifications being incorporated, a newly developed LBM model is able to simulate a collision of a droplet and quiescent surface appropriately. Specifically, the underwater sound was generated by the collision of the droplet with the water surface and it propagates either in a droplet and liquid phase, as well as into the air. At the same time, small air bubbles are generated and thus make the sound propagation to be a dipole type.

Free Research Field

数値流体力学

Academic Significance and Societal Importance of the Research Achievements

気液界面から発する空中音ならびに水中音，あるいはこれらの音と気液界面との相互作用は，多くの解明すべき問題が残っており，その詳細を調べる方法として，数値シミュレーションが有力である。
本研究の学術的意義は，格子ボルツマン法を導入することにより，これらの要素をひとつのモデルの中に組み込み，これらの要素を同時に直接シミュレーションできる手法を開発した点にある。気液界面の様々な要素が複雑に絡みあった気液界面と音波との相互干渉現象を解明する上において強力な解析手段が与えられたことになる。