A phase-field model for fluid-structure interaction

JOURNAL OF COMPUTATIONAL PHYSICS

卷:372

Article

Mokbel, Dominic¹  Abels, Helmut²  Aland, Sebastian^1,3 

[1] Tech Univ Dresden, Inst Wissensch Rechnen, D-01062 Dresden, Germany

[2] Univ Regensburg, Fak Math, D-93040 Regensburg, Germany

[3] Hsch Tech & Wirtschaft Dresden, Fak Informat Math, D-01069 Dresden, Germany

关键词: Fluid-structure interaction;    Phase-field;    Diffuse interface;    Viscoelasticity;    Contact problem;    Fully Eulerian;   

DOI  :  10.1016/j.jcp.2018.06.063

来源: Elsevier

【 摘 要 】

In this paper, we develop a novel phase-field model for fluid-structure interaction (FSI), that is capable to handle very large deformations as well as topology changes like contact of the solid to a wall. The model is based on a fully Eulerian description of the velocity field in both, the fluid and the elastic domain. Viscous and elastic stresses in the Navier-Stokes equations are restricted to the corresponding domains by multiplication with their characteristic functions. The solid is described as a hyperelastic neo-Hookean material and the elastic stress is obtained by solving an additional Oldroyd-B - like equation. Thermodynamically consistent forces are derived by energy variation. The convergence of the derived equations to the traditional sharp interface formulation of fluid-structure interaction is shown by matched asymptotic analysis. The model is evaluated in a challenging benchmark scenario of an elastic body traversing a fluid channel. A comparison to reference values from Arbitrary Lagrangian Eulerian (ALE) simulations shows very good agreement. We highlight some distinct advantages of the new model, like the avoidance of re-triangulations and the stable inclusion of surface tension. Further, we demonstrate how simple it is to include contact dynamics into the model, by simulating a ball bouncing off a wall. We extend this scenario to include adhesion of the ball, which to our knowledge, cannot be simulated with any other FSI model. While we have restricted simulations to fluid-structure interaction, the model is capable to simulate any combination of viscous fluids, visco-elastic fluids and elastic solids. (C) 2018 Elsevier Inc. All rights reserved.

【 授权许可】

Free