Article
Mathematics, Applied
Johannes Holke, David Knapp, Carsten Burstedde
Summary: In this work, we discuss parallel algorithms for computing the ghost layer in computational, distributed memory, recursively adapted meshes. The ghost layer is necessary for executing parallel, element-based computer simulations. We present a design with modularity of algorithms and data structures, targeting adaptive, nonconforming forest-of-trees meshes with mixed element shapes like cubes, prisms, and tetrahedra.
SIAM JOURNAL ON SCIENTIFIC COMPUTING
(2021)
Article
Computer Science, Interdisciplinary Applications
Romain Janodet, Carlos Guillamon, Vincent Moureau, Renaud Mercier, Ghislain Lartigue, Pierre Benard, Thibaut Menard, Alain Berlemont
Summary: This article presents a parallel and robust strategy for simulating turbulent incompressible two-phase flows on unstructured grids in complex geometries. The combination of a narrow-band accurate conservative level set/ghost-fluid framework with isotropic adaptive mesh refinement allows for accurate capture of interface dynamics and topology. The method has been validated through various tests and examples, demonstrating its spatial convergence, robustness, and efficiency. It also showcases the computational advantages of adaptive mesh refinement for simulating complex turbulent flows with large density ratios.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Yadong Zeng, Anqing Xuan, Johannes Blaschke, Lian Shen
Summary: A unified adaptive level set framework for incompressible two-phase flows is developed using a multi-level collocated grid, along with synchronization operations and a multilevel re-initialization method. The framework shows good numerical implementation and mass conservation, successfully resolving various canonical problems. Additionally, efficiency and significant speedup are demonstrated in a three-dimensional dam breaking simulation.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Astronomy & Astrophysics
Milinda Fernando, David Neilsen, Yosef Zlochower, Eric W. Hirschmann, Hari Sundar
Summary: We present results from the new Dendro-GR code, which includes simulations of binary black hole mergers for mass ratios up to q = 16. The code utilizes wavelet adaptive multiresolution and an octree-based data structure to generate an unstructured grid adapted to the spacetime geometry. Validation of the code is achieved through comparisons to LazEv, demonstrating good scaling, improved convergence properties, and efficient usage of computational resources.
Article
Mathematics, Applied
Rony Keppens, Jannis Teunissen, Chun Xia, Oliver Porth
Summary: MPI-AMRVAC is an open-source, block-grid adaptive framework for hyperbolic/parabolic partial differential equations. It can cover system PDEs of any dimensionality, and has recently added a parallel multi-grid solver for new avenues of extension.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Environmental Sciences
Georgios Kourakos, Thomas Harter
Summary: The study introduces a more rigorous approach for increasing mesh density in groundwater simulations using Adaptive Mesh Refinement (AMR), leading to higher accuracy in areas with steep gradients. The proposed method demonstrates viability in 2D hypothetical examples and a 3D test case, automatically resolving solutions with appropriate higher density for localized refinement and accuracy.
WATER RESOURCES RESEARCH
(2021)
Article
Astronomy & Astrophysics
Sarah Renkhoff, Daniela Cors, David Hilditch, Bernd Bruegmann
Summary: When a numerical simulation needs to deal with a physics problem that has a wide range of time-dependent length scales, dynamically adaptive discretizations can be the preferred method. A major upgrade to the numerical relativity code BAMPS is presented, incorporating fully adaptive, physics-agnostic hp refinement. The foundations of mesh refinement in the context of spectral element methods, the algorithm used for refinement in BAMPS, and several indicator functions used to drive it are described. The performance, scalability, and accuracy of the code in treating various 1D and 2D example problems are tested, demonstrating clear improvements over static mesh configurations. In particular, a simple nonlinear wave equation, the evolution of a real scalar field minimally coupled to gravity, and nonlinear gravitational waves are considered.
Article
Computer Science, Information Systems
Xianbing Wang, Peng Zhao, Gaofeng Wang
Summary: In this paper, a novel adaptive mesh generation technique is proposed for efficient electromagnetic simulation of RFICs. Various adaptive mesh treatments, such as mesh projection, edge refinement, and via polymerization, are utilized to improve the accuracy and efficiency of electromagnetic computations. Numerical examples are provided to validate the computational accuracy and efficiency of the proposed technique.
Review
Mathematics, Applied
Pascal Mossier, Daniel Appel, Andrea D. Beck, Claus-Dieter Munz
Summary: In this paper, we present an hp-adaptive discretization method using a level-set ghost-fluid approach to simulate compressible multiphase flows. The method combines the accuracy of the high-order discontinuous Galerkin method and the robustness of the Finite Volume scheme to capture shocks and phase interfaces. Results show that the hybrid adaptive discretization can efficiently and accurately handle complex multiphase flow problems.
JOURNAL OF SCIENTIFIC COMPUTING
(2023)
Article
Computer Science, Interdisciplinary Applications
Hui Liu, Peng Wei, Michael Yu Wang
Summary: This paper proposes an adaptive parameterized level set topology optimization method (APLSM) using a bilinear basis function and applies CPU parallel computing strategy. The method avoids solving an additional linear system and improves computational efficiency. It can also design structures with high geometric complexity and has been verified effective in 2D and 3D problems.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Mechanics
Wenqiang Xu, Yu Li, Hanzhang Li, Sheng Qiang, Chengpeng Zhang, Caihong Zhang
Summary: This article introduces a multi-level adaptive mesh refinement technique for solving the contradiction between calculation efficiency and accuracy of the phase-field method. The technique achieves good results in crack simulation and has potential engineering applications.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Thermodynamics
J. Potgieter, L. Lombaard, J. Hannay, M. A. Moghimi, P. Valluri, J. P. Meyer
Summary: This study presents a new interface-tracking adaptive mesh refinement model for research on microchannel flow boiling. The model reduces computational costs while maintaining accuracy, and is capable of simulating two-phase flow in three dimensions.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Multidisciplinary
W. Abdel Nour, A. Larcher, D. Serret, P. Meliga, E. Hachem
Summary: This paper presents a method for topology optimization of duct flows based on the Navier-Stokes equations, using anisotropic mesh adaptation. The method combines an immersed volume method with level set representations to accurately describe fluid-solid interfaces. The proposed approach reduces computational burden and improves accuracy compared to classical optimization schemes.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Xianbao Duan, Yichen Li, Hongxia Tan, Yangyang Li
Summary: In this study, a level set based adaptive mesh method is proposed for minimizing drag in incompressible flow governed by Stokes equations. Shape sensitivity analysis of the cost functional is derived, and two levels of meshes are adopted during the optimization process. By using a coarse mesh for evolving the level set function and further refining it near the interfaces, computational cost is significantly reduced compared to using a uniform mesh over the entire domain with the same resolution. Additionally, obtaining the shape derivative value on the boundary implicitly is a challenging task in classical optimal shape design problems.
INTERNATIONAL JOURNAL OF NONLINEAR SCIENCES AND NUMERICAL SIMULATION
(2022)
Article
Computer Science, Interdisciplinary Applications
Oscar Antepara, Nestor Balcazar, Assensi Oliva
Summary: This article introduces a parallel adaptive mesh refinement strategy for two-phase flows using tetrahedral meshes, which combines a conservative level-set method and tetrahedral adaptive meshes within a finite volume framework. The approach involves cell-based refinement and mesh adaptation based on physics-based criteria. The study demonstrates the capability and accuracy of 3D adapted tetrahedral grids in simulating two-phase flows with surface tension.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Jin Bao, Zhaoli Guo
Summary: At the equilibrium state of a two-phase fluid system, the chemical potential is constant and the velocity is zero. However, it is challenging to capture this equilibrium state accurately in numerical simulations, resulting in inconsistent thermodynamic interfacial properties and spurious velocities. Therefore, numerical schemes with well-balanced properties are preferred for simulating two-phase flows.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Brian C. Vermeire
Summary: This study presents a framework for implicit large eddy simulation (ILES) of incompressible flows by combining the entropically damped artificial compressibility (EDAC) method with the flux reconstruction (FR) approach. Experimental results demonstrate that the method is accurate and stable for low-order solutions, while higher-order solutions exhibit significantly higher accuracy and lower divergence error compared to reference direct numerical simulation.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Mijian Li, Rui Wang, Xinyu Guo, Xinyu Liu, Lianzhou Wang
Summary: In this study, the flow mechanisms around wall-mounted structures were investigated using Large Eddy Simulation (LES). The impact of inflow turbulence on the flow physics, dynamic response, and hydrodynamic performance was explored. The results revealed strong interference between velocity fluctuations and the wake past the cylinder, as well as significant convection effects in the far wake region.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Donatella Passiatore, Luca Sciacovelli, Paola Cinnella, Giuseppe Pascazio
Summary: A high-order shock-capturing central finite-difference scheme is evaluated for numerical simulations of hyper-sonic high-enthalpy flows out of thermochemical equilibrium. The scheme utilizes a tenth-order accurate central-difference approximation of inviscid fluxes, along with high-order artificial dissipation and shock-capturing terms. The proposed approach demonstrates accuracy and robustness for a variety of thermochemical non-equilibrium configurations.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Philipp Bahavar, Claus Wagner
Summary: Condensation is an important aspect in flow applications, and simulating the gas phase and tracking the deposition rates of condensate droplets can capture the effects of surface droplets on the flow while reducing computational costs.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Andras Szabo, Gyorgy Paal
Summary: This paper introduces an efficient calculation method, the parabolized stability equations (PSE), for solving stability equations. By calculating LU factorization once in each marching step, the time spent on solving linear systems of equations can be significantly reduced. Numerical experiments demonstrate the effectiveness of this method in reducing the solution time for linear equations, and its applicability to similar problems.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
A. Khalifa, M. Breuer
Summary: This study evaluates a recently developed data-driven model for collision-induced agglomerate breakup in high mass loading flows. The model uses artificial neural networks to predict the post-collision behavior of agglomerates, reducing computational costs compared to coupled CFD-DEM simulations.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Chunmei Du, Maojun Li
Summary: This paper considers the bilayer shallow water wave equations in one-dimensional space and presents an invariant domain preserving DG method to avoid Kelvin-Helmholtz instability.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jean-Michel Tucny, Mihir Durve, Andrea Montessori, Sauro Succi
Summary: The prediction of non-equilibrium transport phenomena in disordered media is a challenging problem for conventional numerical methods. Physics-informed neural networks (PINNs) show potential for solving this inverse problem. In this study, PINNs were used to successfully predict the velocity field of rarefied gas flow, and AdamW was found to be the best optimizer.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Min Gao, Pascal Mossier, Claus-Dieter Munz
Summary: In recent decades, the arbitrary Lagrangian-Eulerian (ALE) approach has gained popularity in dealing with fluid flows with moving boundaries. This paper presents a novel algorithm that combines the ALE finite volume (FV) and ALE discontinuous Galerkin (DG) methods into a stable and efficient hybrid approach. The main challenge of this mixed ALE FV and ALE DG method is reducing the inconsistency between the two discretizations. The proposed algorithm is implemented into a loosely-coupled fluid-structure interaction (FSI) framework and is demonstrated through various benchmark test cases and complex scenarios.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Dawid Strzelczyk, Maciej Matyka
Summary: In this study, the numerical convergence of the Meshless Lattice Boltzmann Method (MLBM) is investigated through three benchmark tests. The results are compared to the standard Lattice Boltzmann Method (LBM) and the analytical solution of the Navier-Stokes equation. It is found that MLBM outperforms LBM in terms of error value for the same number of nodes discretizing the domain.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Kanishka Bhattacharya, Tapan Jana, Amit Shaw, L. S. Ramachandra, Vishal Mehra
Summary: In this work, an adaptive algorithm is developed to address the issue of tensile instability in Smoothed Particle Hydrodynamics (SPH) by adjusting the shape of the kernel function to satisfy stability conditions. The effectiveness of the algorithm is demonstrated through dispersion analysis and fluid dynamics simulations.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Luis Laguarda, Stefan Hickel
Summary: We propose several enhancements to improve the accuracy and performance of the digital filter turbulent inflow generation technique, such as introducing a more realistic correlation function and varying target length scales. Additionally, we suggest generating inflow data in parallel at a prescribed time interval to improve computational performance. Based on the results of large-eddy simulations, these enhancements have shown to be beneficial. Suppressing streamwise velocity fluctuations at the inflow leads to the fastest relaxation of pressure fluctuations. However, this approach increases the adaptation length, which can be shortened by artificially increasing the wall-normal Reynolds stresses.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Constantin Zenz, Michele Buttazzoni, Tobias Florian, Katherine Elizabeth Crespo Armijos, Rodrigo Gomez Vazquez, Gerhard Liedl, Andreas Otto
Summary: A new model for compressible multiphase flows involving sharp interfaces and phase change is presented, with a focus on the treatment of compressibility and phase change in the multiphase fluid flow model. The model's accuracy and suitability are demonstrated through comparisons with experimental observations.
COMPUTERS & FLUIDS
(2024)
Article
Computer Science, Interdisciplinary Applications
Joseph O'Connor, Sylvain Laizet, Andrew Wynn, Wouter Edeling, Peter V. Coveney
Summary: This article aims to apply uncertainty quantification and sensitivity analysis to the direct numerical simulation (DNS) of low Reynolds number wall-bounded turbulent channel flow. By using a highly scalable DNS framework and UQ techniques, the study evaluates the influence of different numerical parameters on the simulation results without explicitly modifying the code. The findings provide guidance for numerical simulations of wall-bounded turbulent flows.
COMPUTERS & FLUIDS
(2024)