Abstract
We present an adaptive simulation framework for binary-fluid flows, based on the Abels–Garcke–Grün Navier–Stokes–Cahn–Hilliard (AGG NSCH) diffuse-interface model. The adaptive-refinement procedure is guided by a two-level hierarchical a-posteriori error estimate, and it effectively resolves the spatial multiscale behavior of the diffuse-interface model. To improve the robustness of the solution procedure and avoid severe time-step restrictions for small-interface thicknesses, we introduce an ɛ-continuation procedure, in which the diffuse interface thickness (ɛ) are enlarged on coarse meshes, and the mobility is scaled accordingly. To further accelerate the computations and improve robustness, we apply a modified Backward Euler scheme in the initial stages of the adaptive-refinement procedure in each time step, and a Crank–Nicolson scheme in the final stages of the refinement procedure. To enhance the robustness of the nonlinear solution procedure, we introduce a partitioned solution procedure for the linear tangent problems in Newton's method, based on a decomposition of the NSCH system into its NS and CH subsystems. We conduct a systematic investigation of the conditioning of the monolithic NSCH tangent matrix and of its NS and CH subsystems for a representative 2D model problem. To illustrate the properties of the presented adaptive simulation framework, we present numerical results for a 2D oscillating water droplet suspended in air, and we validate the obtained results versus those of a corresponding sharp-interface model.
Original language | English |
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Article number | 115563 |
Number of pages | 35 |
Journal | Computer Methods in Applied Mechanics and Engineering |
Volume | 400 |
DOIs | |
Publication status | Published - 1 Oct 2022 |
Funding
This research was partly conducted within the Industrial Partnership Program Fundamental Fluid Dynamics Challenges in Inkjet Printing (FIP), a joint research program of Canon Production Printing, Eindhoven University of Technology, University of Twente, and the Netherlands Organization for Scientific Research (NWO). T.H.B. Demont and C. Diddens gratefully acknowledge financial support through the FIP program . All simulations have been performed using the open source software package Nutils [47] ( www.nutils.org ).
Keywords
- Adaptive refinement
- Binary-fluid flows
- Diffuse-interface models
- Navier–Stokes–Cahn–Hilliard equations
- Partitioned solution methods
- ɛ-continuation