講演情報
[U02-03]高粘度混相流コードの開発：マグマダイナミクスシミュレーションにむけて
*古市 幹人1、西浦 泰介1 (1.海洋研究開発機構)
キーワード：
マグマ、固液混相流、ストークス流れ、個別要素法、メルトルーフ、数値手法
For geodynamical magmatic studies such as crystal settling at the melting roof of a magma chamber, we develop a robust and efficient simulation scheme for solving high-viscosity fluid and particle dynamics in a coupled computational fluid dynamics and discrete element method (CFD--DEM) framework. The high-viscosity fluid is treated by the Stokes-flow approximation, where the fluid interacts with particles via the drag force in a cell-averaged manner. The particles are tracked with contact forces by DEM. To efficiently solve such Stokes--DEM coupled equations, we propose two key techniques. One is formulation of particle motion without the inertial term, allowing a larger time step at higher viscosities. The other is a semi-implicit treatment of the cell-averaged particle velocity in the fluid equation to stabilize the calculation. We will explain some details of our model developments in the presentation. A series of numerical experiments shows that our proposed scheme can handle sinking particles in a high-viscosity fluid; such problems are difficult for the conventional CFD--DEM method. Then we will discuss our targeting geodynamical problems tackled with this simulation method.