Article
Mechanics
Chenlin Zhu, Lijuan Qian, Zhaowu Lin, Zhaosheng Yu
Summary: This study investigates the turbulent channel flow of a binary mixture of finite-size neutrally buoyant ellipsoidal particles using a parallel direct-forcing fictitious domain method. The results reveal that the variation of particle volume concentration has an impact on the flow properties under different friction Reynolds numbers and particle aspect ratios.
Article
Computer Science, Interdisciplinary Applications
Manuel Garcia-Villalba, Blanca Fuentes, Jan Dusek, Manuel Moriche, Markus Uhlmann
Summary: This paper presents a simple modification of the direct-forcing immersed boundary method (IBM) to be applied to particulate flows with solid-to-fluid density ratios around unity. The modified method involves a direct particle velocity update and the application of forcing term to the entire space occupied by the immersed solid object. The method has been validated in three test cases and shows good agreement with reference data, making it a cost-efficient and accurate approach for simulating fluid systems with density-matched solid particles.
COMPUTERS & FLUIDS
(2023)
Article
Computer Science, Interdisciplinary Applications
Ang Li, Tsorng-Whay Pan, Roland Glowinski
Summary: This article discusses the simulation of neutrally buoyant particles of non-symmetric shape in non-Newtonian shear-thinning fluids using a Lagrange multiplier based fictitious domain method (DLM/FD). The study compares numerical solutions of steady Poiseuille flow with exact solutions in a two-dimensional channel, and explores the impact of shear-thinning on the movement of a self-propelled swimmer composed of two disks.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2022)
Article
Physics, Mathematical
Cheng Wang, Pengtao Sun
Summary: An augmented Lagrangian Uzawa iterative method is proposed for solving double saddle-point systems with semi definite (2,2) block, with convergence proven under the assumption of a unique solution. The method is also applied to elliptic interface problems, with numerical experiments validating theoretical results and studying the method's performance.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
Xinchen Zhang, Francesco Zonta, Zhao F. Tian, Graham J. Nathan, Rey C. Chin, Alfredo Soldati
Summary: This paper investigates the dynamics of semi-and neutrally-buoyant particles in three-dimensional, stably-stratified turbulent channel flow. Particles released in different regions exhibit different behaviors, leading to distinct evolution of the particle swarms.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Computer Science, Interdisciplinary Applications
Martin Reder, Daniel Schneider, Fei Wang, Simon Daubner, Britta Nestler
Summary: The distributed Lagrange multiplier/fictitious domain method in a phase-field formulation allows for simulation of rigid bodies in incompressible fluid flow, with the capability to handle complex boundary geometries and changes in shape during simulations. Multiple numerical experiments demonstrate its effectiveness in simulating problems involving differently shaped rigid bodies and particulate flows within complex boundary geometries like foam structures.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2021)
Article
Mechanics
Wenwei Liu, Chuan-Yu Wu
Summary: This study investigates the inertial migration of neutrally buoyant circular particles in planar Poiseuille flow with thermal convection, finding that the lateral equilibrium position of particles shifts from above to below the centerline when the channel Grashof number reaches a critical value. The critical Grashof number is dependent on the channel Reynolds number and the particle-to-channel size ratio, and a unified Grashof number is introduced to consider the combined effects of thermal convection and particle size. Additionally, the occurrence of equilibrium position transition is not sensitive to initial conditions, but the exact transition point does depend on factors such as the initial position of the particle and the fluid flow state.
Article
Engineering, Mechanical
David Engler Faleiros, Marthijn Tuinstra, Andrea Sciacchitano, Fulvio Scarano
Summary: The study investigates the behavior of nearly neutrally buoyant tracers using experiments and numerical simulations, and introduces a new model for estimating particle slip velocity. The findings show that the particle slip velocity depends on the particle-to-fluid density ratio, particle Reynolds number, and frequency of local flow fluctuations.
EXPERIMENTS IN FLUIDS
(2021)
Article
Materials Science, Multidisciplinary
Kui Liu, Ang Zhao, Zhendong Hu
Summary: The fat boundary method (FBM), a fictitious domain method proposed for Poisson problems with small perforations, can achieve higher accuracy around holes. Despite strict restrictions on the original FBM, this article attempts to break these limitations and apply the method to elasticity by introducing Neumann boundary conditions and proposing a dual fat boundary method. The conditional convergence of the algorithm is mathematically proven and compared with the Lagrange multiplier method to show that FBM is a weak imposition method.
MATHEMATICS AND MECHANICS OF SOLIDS
(2021)
Article
Computer Science, Interdisciplinary Applications
Kirill Goncharuk, Oz Oshri, Yuri Feldman
Summary: A novel formulation of the direct forcing immersed boundary (IB) method is presented, which treats it as an integral part of a SIMPLE method for simulating incompressible flows. The incompressibility and no-slip kinematic constraints are treated implicitly as distributed Lagrange multipliers and are fully coupled with each other. The developed methodology shows promising capabilities in simulating shear-and buoyancy-driven confined flows with stationary immersed bodies.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Tsorng-Whay Pan, Shang-Huan Chiu
Summary: In this article, a numerical method for simulating sedimentation of balls in a three-dimensional channel filled with an Oldroyd-B fluid is presented. The method combines a distributed Lagrange multiplier/fictitious domain method with a factorization approach. The validity of the method is confirmed by comparing the obtained results with those reported in literature. Additionally, the influence of fluid elasticity on the formation of ball chain in Oldroyd-B fluids is studied, showing the capability of the method.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Mathematics, Applied
A. N. Temirbekov, L. N. Temirbekova, B. T. Zhumagulov
Summary: The article discusses the study of the extreme problem of the fictitious domain method using the Lagrange functional and a multiplier on the actual boundary. A computational algorithm based on conjugate optimization is developed, allowing the construction of a homogeneous difference scheme in the extended domain. The gradient method is used for iterative refinement to minimize the Lagrange functional. The effectiveness of the approach is demonstrated using the Burgers equation and later applied to solve the Navier-Stokes equation.
APPLIED AND COMPUTATIONAL MATHEMATICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Junjie Hu, Hui Pan, Fangqing Zhang, Huili Wang, Gaojie Liu, Yongyu Wang
Summary: This study investigates the motion of a pair of neutrally buoyant circular particles with different sizes in a lid-driven square cavity using the lattice Boltzmann method. The results show that the motion and trajectories of circular particles with different sizes are quite different from those with identical sizes, suggesting a possible method to separate them. However, the effectiveness of separation may be limited at low Reynolds numbers.
INTERNATIONAL JOURNAL OF MODERN PHYSICS C
(2022)
Article
Physics, Fluids & Plasmas
Yi Liang, Cheng Wang, Pengtao Sun
Summary: This paper proposes an interface-fitted fictitious domain finite element method for simulating fluid-rigid particle interaction problems with rotated particles and small displacement. The method employs an interface-fitted mesh to accurately capture the fluid-rigid particle interface and improves solution accuracy near the interface. A linearization and decoupling process is presented to release the constraint between fluid and rigid particle velocities, making the numerical method easy to implement. Numerical experiments using different moving interface-fitted meshes show that the proposed method has good accuracy in simulating neutrally buoyant particles in plane shear flow. The method can be easily extended to fluid-structure interaction problems involving different fluid states, different structure shapes, and large displacements or deformations.
Article
Physics, Fluids & Plasmas
Wenwei Liu, Chuan-Yu Wu
Summary: In this study, numerical simulations were conducted to investigate the inertial migration of non-neutrally buoyant particles with different density ratios in a linear shear flow channel under thermal convection. The results showed that the migration behavior of particles is influenced by different lift forces, resulting in distinctive migration patterns.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Physics, Applied
Che-Ming Shih, Chun-Fei Kung, Chien-Cheng Chang, Tsorng-Whay Pan
APPLIED PHYSICS LETTERS
(2015)
Article
Physics, Mathematical
Xiting Niu, Lingling Shi, Tsorng-Whay Pan, Roland Glowinski
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2015)
Article
Computer Science, Interdisciplinary Applications
Lingling Shi, Suncica Canic, Annalisa Quaini, Tsorng-Whay Pan
JOURNAL OF COMPUTATIONAL PHYSICS
(2016)
Article
Mechanics
Tsorng-Whay Pan, Roland Glowinski
JOURNAL OF NON-NEWTONIAN FLUID MECHANICS
(2017)
Article
Mathematics, Applied
Aixia Guo, Tsorng-Whay Pan, Jiwen He, Roland Glowinski
COMPUTATIONAL METHODS IN APPLIED MATHEMATICS
(2017)
Article
Mathematics
Shihai Zhao, Yao Yu, Tsorng-Whay Pan, Roland Glowinski
CHINESE ANNALS OF MATHEMATICS SERIES B
(2018)
Article
Mechanics
Liang-Hsia Tsai, Chien-Cheng Chang, Tsorng-Whay Pan, Roland Glowinski
INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS
(2018)
Article
Computer Science, Interdisciplinary Applications
Tsorng-Whay Pan, Aixia Guo, Shang-Huan Chiu, Roland Glowinski
JOURNAL OF COMPUTATIONAL PHYSICS
(2018)
Article
Biophysics
Xiting Niu, Tsorng-Whay Pan, Roland Glowinski
BIOMECHANICS AND MODELING IN MECHANOBIOLOGY
(2015)
Article
Mechanics
Tsorng-Whay Pan, Roland Glowinski
Article
Mechanics
Tsorng-Whay Pan, Shang-Huan Chiu, Roland Glowinski
Article
Mechanics
Tsorng-Whay Pan, Ang Li, Roland Glowinski
Summary: This article investigates the equilibrium radial positions of neutrally buoyant balls in circular Poiseuille flows through direct numerical simulations, revealing different equilibrium positions and stability under varying Reynolds numbers. At high Reynolds numbers, a single ball exhibits two equilibrium positions, while a two-ball train becomes unstable at higher Reynolds numbers, showing periodic interactions and exhibiting an unstable phenomenon beyond a critical Reynolds number.
Article
Computer Science, Interdisciplinary Applications
Ang Li, Tsorng-Whay Pan, Roland Glowinski
Summary: This article discusses the simulation of neutrally buoyant particles of non-symmetric shape in non-Newtonian shear-thinning fluids using a Lagrange multiplier based fictitious domain method (DLM/FD). The study compares numerical solutions of steady Poiseuille flow with exact solutions in a two-dimensional channel, and explores the impact of shear-thinning on the movement of a self-propelled swimmer composed of two disks.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2022)
Article
Physics, Fluids & Plasmas
Tsorng-Whay Pan, Roland Glowinski
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)
