Gradient-descent-like scheme for the Allen–Cahn equation

The phase-field equations have many attractive characteristics. First, phase separation can be induced by the phase-field equations. It transforms from a single homogeneous mixture to two distinct phases in a nascent state. Second, the solution of the phase-field equations is bounded by a finite val...

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Main Author: Dongsun Lee
Format: Article
Language:English
Published: AIP Publishing LLC 2023-08-01
Series:AIP Advances
Online Access:http://dx.doi.org/10.1063/5.0161876
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author Dongsun Lee
author_facet Dongsun Lee
author_sort Dongsun Lee
collection DOAJ
description The phase-field equations have many attractive characteristics. First, phase separation can be induced by the phase-field equations. It transforms from a single homogeneous mixture to two distinct phases in a nascent state. Second, the solution of the phase-field equations is bounded by a finite value. It is beneficial to ensure numerical stability. Third, the motion of the interface can be described by geometric features. It is helpful for expressing natural phenomena in mathematical terms. Fourth, the phase-field equations possess the energy dissipation law. This law is about degeneration and decay. It tells us in thermodynamics that all occurrences are irreversible processes. In this paper, we would like to investigate the numerical implementation of the Allen–Cahn (AC) equation, which is the classical one of the phase-field equations. In phase field modeling, the binary phase system is described using a continuous variable called the order parameter. The order parameter can be categorized into two forms: conserved, which represents the physical property such as concentration or mass, and non-conserved, which does not have the conserved physical property. We consider both the non-conservative and conservative AC equations. Our interest is more precisely to scrutinize the utilization of the discrete Laplacian operator in the AC equation by considering the conservative and non-conservative order parameter ϕ. Constructing linearly implicit methods for solving the AC equation, we formulate a gradient-descent-like scheme. Therefore, reinterpreting the implicit scheme for the AC equation, we propose a novel numerical scheme in which solutions are bounded by 1 for all t > 0. Together with the conservative Allen–Cahn equation, our proposed scheme is consistent when mass is conserved as well. From a numerical point of view, a linear, unconditionally energy stable splitting scheme is transformed into a gradient-descent-like scheme. Various numerical simulations are illustrated to demonstrate the validity of the proposed scheme. We also make distinctions between the proposed one and existing numerical schemes.
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spelling doaj.art-94ad9f9a2d5e4dfeb520c4e71f7610682023-09-08T16:03:29ZengAIP Publishing LLCAIP Advances2158-32262023-08-01138085010085010-1110.1063/5.0161876Gradient-descent-like scheme for the Allen–Cahn equationDongsun Lee0Department of Mathematics Education, Incheon National University, Incheon 21999, Republic of KoreaThe phase-field equations have many attractive characteristics. First, phase separation can be induced by the phase-field equations. It transforms from a single homogeneous mixture to two distinct phases in a nascent state. Second, the solution of the phase-field equations is bounded by a finite value. It is beneficial to ensure numerical stability. Third, the motion of the interface can be described by geometric features. It is helpful for expressing natural phenomena in mathematical terms. Fourth, the phase-field equations possess the energy dissipation law. This law is about degeneration and decay. It tells us in thermodynamics that all occurrences are irreversible processes. In this paper, we would like to investigate the numerical implementation of the Allen–Cahn (AC) equation, which is the classical one of the phase-field equations. In phase field modeling, the binary phase system is described using a continuous variable called the order parameter. The order parameter can be categorized into two forms: conserved, which represents the physical property such as concentration or mass, and non-conserved, which does not have the conserved physical property. We consider both the non-conservative and conservative AC equations. Our interest is more precisely to scrutinize the utilization of the discrete Laplacian operator in the AC equation by considering the conservative and non-conservative order parameter ϕ. Constructing linearly implicit methods for solving the AC equation, we formulate a gradient-descent-like scheme. Therefore, reinterpreting the implicit scheme for the AC equation, we propose a novel numerical scheme in which solutions are bounded by 1 for all t > 0. Together with the conservative Allen–Cahn equation, our proposed scheme is consistent when mass is conserved as well. From a numerical point of view, a linear, unconditionally energy stable splitting scheme is transformed into a gradient-descent-like scheme. Various numerical simulations are illustrated to demonstrate the validity of the proposed scheme. We also make distinctions between the proposed one and existing numerical schemes.http://dx.doi.org/10.1063/5.0161876
spellingShingle Dongsun Lee
Gradient-descent-like scheme for the Allen–Cahn equation
AIP Advances
title Gradient-descent-like scheme for the Allen–Cahn equation
title_full Gradient-descent-like scheme for the Allen–Cahn equation
title_fullStr Gradient-descent-like scheme for the Allen–Cahn equation
title_full_unstemmed Gradient-descent-like scheme for the Allen–Cahn equation
title_short Gradient-descent-like scheme for the Allen–Cahn equation
title_sort gradient descent like scheme for the allen cahn equation
url http://dx.doi.org/10.1063/5.0161876
work_keys_str_mv AT dongsunlee gradientdescentlikeschemefortheallencahnequation