Multiphase parallel computation method to predict and understand disasters caused by gas-liquid-solid interactions

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K11337
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 60100:Computational science-related
• Research Institution: Kyoto University
• Principal Investigator: Ushijima Satoru 京都大学, 学術情報メディアセンター, 教授 (70324655)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: マルチフェイズモデル / 流体固体連成 / 固気液多相場 / 局所洗掘現象 / 浸透流 / 並列計算

Outline of Final Research Achievements

In this study, the applicability of the multiphase parallel computation method has been investigated mainly to the fluid-solid interaction problems. The obtained results are summarised as follows: (1) Hydraulic experiments and numerical predictions were conducted for the local scour on the gravel bed caused by an impinging vertical water jet. It was confirmed that the calculated gravel-bed shapes are in good agreement with the experimental results. In addition, the total traveling length of each gravel particle, contact forces between particles, and pore water pressure were obtained with the computation method. (2) Similar results to (1) were shown in case that the upward vertical flow enters from the bottom of the gravel particles with the computation method. (3) It was shown that the essential characteristics are reasonably calculated for the high viscous fluids, non-Newtonian fluids and seepage flows among the absorbent particles.

Free Research Field

計算科学

Academic Significance and Societal Importance of the Research Achievements

本研究では，マルチフェイズ・並列計算手法の適用性に関する検討を行い，約1万7千個の礫粒子から構成される礫層に水流が作用する流体固体連成現象を適切に数値計算できることが示された．この解法では，個々の礫粒子を複数の四面体要素で表し，礫粒子に作用する流体力は，固体に作用する圧力と粘性応力に相当する計算結果から求める．礫粒子の接触力や移動経路，間隙水圧など，現象解明に役立つ計算結果が得られることが示された．この結果をまとめた論文は，令和2年5月に応用力学論文賞を受賞し，一定の学術的評価が得られたと考えられる．