Article
Mathematics, Applied
Rui Du, Yibo Wang
Summary: In this paper, a novel LBGK model for incompressible time-fractional Navier-Stokes equations with Caputo-type fractional derivative is proposed, where the Caputo derivative is approximated to construct the model, and a numerical example is provided to demonstrate the efficiency of the model.
APPLIED MATHEMATICS LETTERS
(2021)
Article
Mathematics, Applied
Felipe A. Diaz, Ernesto Castillo, Roberto C. Cabrales, Nelson O. Moraga
Summary: This article introduces fractional-step schemes for solving incompressible convective time-dependent flows. The schemes are designed from a fully discrete problem and allow for optimal convergence rates. Results showed that Yosida's methods are more accurate than the projection method, and the use of Newton and Picard-Newton linearization strategies considerably reduces the number of iterations compared with the Picard scheme. The optimized second-order method is more accurate than the classical one and is comparable to the third-order method in the solution of dominant convective flows. The benefits of using high-order time integration schemes are verified.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Mathematics, Applied
Lorenzo Botti, Francesco Carlo Massa
Summary: We propose two Hybrid High-Order (HHO) methods for the incompressible Navier-Stokes equations and investigate their robustness with respect to the Reynolds number. The two methods differ in their pressure-velocity coupling, but both have been numerically validated and shown to be effective and applicable.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Mathematics, Applied
Yu-Ming Chu, Nehad Ali Shah, Praveen Agarwal, Jae Dong Chung
Summary: A hybrid method called variational iteration transform method was implemented to solve fractional-order Navier-Stokes equation in this paper. The solutions of three examples demonstrated the validity of the method, which was found to be efficient, reliable, and easy to implement for various related problems in science and engineering.
ADVANCES IN DIFFERENCE EQUATIONS
(2021)
Article
Mathematics, Applied
Xiaona Cui, Wei Shi, Xuezhi Li, Xin-Guang Yang
Summary: This paper investigates the tempered pullback dynamics of 3-D nonautonomous incompressible Navier-Stokes equations with nonlinear damping and delay in a bounded domain. It proves the existence and uniqueness of weak and strong solutions based on delicate priori estimates, and demonstrates the existence of the minimal family of pullback attractors under appropriate hypotheses on external forces.
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2021)
Article
Engineering, Marine
K. D. Do
Summary: This paper addresses the problem of global asymptotic and local exponential stabilization of a rigid body inside a viscous incompressible fluid described by Navier-Stokes equations within a bounded domain in three dimensional space provided that there is no collision between the rigid body and the boundary of the fluid domain. Due to consideration of less regular initial values of the fluid velocity, the forces and moments induced by the fluid on the rigid body are not able to bound. Therefore, the paper handles fluid work and fluid power on the rigid body in stability and convergence analysis of the closed-loop system. The control design ensures global asymptotic and local exponential stability of the rigid body while the initial fluid velocity is not required to be small and regular but only under no collision between the rigid body and the boundary of the fluid domain.
Article
Mathematics, Applied
Thomas Y. Hou, De Huang
Summary: In this paper, the potential singularity behavior of the 3D incompressible axisymmetric Euler equations with smooth initial data of finite energy is investigated. It is found that the introduction of numerical viscosity leads to a locally self-similar blowup phenomenon.
PHYSICA D-NONLINEAR PHENOMENA
(2022)
Article
Mechanics
Niklas Fehn, Martin Kronbichler, Peter Munch, Wolfgang A. Wall
Summary: This study contributes to the investigation of the well-known energy dissipation anomaly in inviscid limit by conducting high-resolution numerical simulations of the three-dimensional Taylor-Green vortex problem. The interesting observation is made that the kinetic energy evolution does not tend towards exact energy conservation as the spatial resolution of numerical scheme increases. This raises the question of whether the results obtained can be seen as a numerical confirmation of the famous energy dissipation anomaly and elaborates on an indirect approach for the identification of finite-time singularities based on energy arguments.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mathematics, Applied
Xuyang Na, Xuejun Xu
Summary: This paper presents a nonoverlapping domain decomposition method for Stokes equations using mixed finite elements with discontinuous pressures. Both conforming and nonconforming finite element spaces are considered for velocities. By employing Robin boundary conditions, the indefinite Stokes problem is reduced to a positive definite problem for the interface Robin transmission data. A new preconditioner for the Stokes problem is proposed based on the Robin-type domain decomposition method, with numerical results provided to support the theoretical findings.
APPLIED NUMERICAL MATHEMATICS
(2022)
Article
Mathematics, Applied
Wei Shi, Xin-Guang Yang, Lin Shen
Summary: This paper investigates the global well-posedness of a fluid-solid interaction model with vorticity, which is described as a hyperbolic-parabolic coupled system along the conjugate boundary. The fluid is governed by the incompressible Navier-Stokes equation with vorticity, while the elastic solid is modeled by the wave equation. The global existence of weak solution and uniqueness of the coupled system are proven using the energy method, delicate estimates, and the truncation-polishing technique to overcome the lack of smoothness in the variational form. (c) 2023 Elsevier B.V. All rights reserved.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Mathematics, Applied
Yani Feng, Qifeng Liao, David Silvester
Summary: In this paper, a nonoverlapping Robin-type multi-domain decomposition method based on stabilized Q(1)-P-0 mixed approximation (RMDD-Q(1)-P-0) is presented for incompressible flow problems. The global equations are decomposed into local problems through Robin-type domain decomposition, which are solved using the local jump stabilized Q(1)-P-0 approximation. It is proven that the RMDD-Q(1)-P-0 solutions converge to the standard global Q(1)-P-0 solutions for the Stokes problem. Numerical experiments show that RMDD-Q(1)-P-0 significantly improves the scalability of the stabilized Q(1)-P-0 approximation. The codes used in the experiments are available online.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Automation & Control Systems
K. D. Do
Summary: This paper considers the problem of boundary feedback stabilization of an elastic body surrounding a viscous incompressible fluid. It gives a proof of global existence of a weak solution of the closed-loop system and handles the issue of unbounded forces induced by the fluid on the elastic body due to less regular initial values of the fluid velocity.
Article
Mathematics, Applied
Haibo Cui, Lei Yao
Summary: This paper considers the initial-boundary value problem of the coupled inhomogeneous incompressible Navier-Stokes equations and Vlasov-Boltzmann equation for the moderately thick spray in three-dimensional space. The global existence of weak solutions is established using an approximation scheme, a fixed point argument, and the weak convergence method.
APPLIED MATHEMATICS LETTERS
(2021)
Article
Mathematics, Applied
Christoph Lohmann, Stefan Turek
Summary: This work presents a new global-in-time solution strategy for incompressible flow problems, which utilizes the pressure Schur complement (PSC) approach in constructing a space-time multigrid algorithm. The strategy involves blocking the linear systems of equations associated with individual time steps into a single all-at-once saddle point problem for velocity and pressure unknowns, and then using the pressure Schur complement to eliminate the velocity fields and set up a linear system for pressure variables only. This multigrid solver is extended to solve the nonlinear Navier-Stokes equations using Newton's method for linearization of the global-in-time problem.
JOURNAL OF MATHEMATICAL FLUID MECHANICS
(2023)
Article
Mathematics, Applied
Bo Zheng, Yueqiang Shan
Summary: This paper introduces a three-step Oseen-linearized finite element method for the 2D/3D steady incompressible Navier-Stokes equations with nonlinear damping term. We theoretically analyze the stability of the method and derive optimal error estimates of the finite element solutions. Numerical experiments support the theoretical analysis and demonstrate the effectiveness of the proposed method.
NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS
(2023)
Article
Computer Science, Interdisciplinary Applications
Herbert Owen, Georgios Chrysokentis, Matias Avila, Daniel Mira, Guillaume Houzeaux, Ricard Borrell, Juan Carlos Cajas, Oriol Lehmkuhl
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2020)
Article
Mechanics
G. Houzeaux, M. Garcia-Gasulla, J. C. Cajas, R. Borrell, A. Santiago, C. Moulinec, M. Vazquez
INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS
(2020)
Article
Engineering, Mechanical
Alfonso Santiago, Miguel Zavala-Ake, Ricard Borrell, Guillaume Houzeaux, Mariano Vazquez
JOURNAL OF FLUIDS AND STRUCTURES
(2020)
Editorial Material
Mechanics
Guillaume Houzeaux, Marta Garcia-Gasulla
INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS
(2020)
Article
Nuclear Science & Technology
Alejandro Soba, Mauricio E. Cazado, Guillaume Houzeaux, Albert Gutierrez-Milla, Mervi J. Mantsinen, Xavier Saez
Summary: The study presents significant improvements and validations of a deterministic neutron transport code dedicated to solving the Boltzmann Transport Equation. The code is integrated as a module in the Alya software package using multi-group energy discretization and FEM on unstructured meshes to treat complex domains. Real base expressions are used to introduce the anisotropy of the scattering medium.
FUSION ENGINEERING AND DESIGN
(2021)
Article
Engineering, Mechanical
C. Samaniego, J. Ulloa, P. Rodriguez, G. Houzeaux, M. Vazquez, E. Samaniego
Summary: This study contributes to the understanding of localized failure mechanisms using phase fields in a variational framework. It introduces a new degradation function to distinguish between plastic strain localization and ductile fracture mechanisms, and proposes a parallel implementation of the phase-field approach to tackle potential high computational costs. Several examples demonstrate the capabilities of this implementation in capturing different failure mechanisms.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Mechanics
J. C. Cajas, D. Pastrana, I Rodriguez, O. Lehmkuhl, G. Houzeaux, M. Vazquez, C. Trevino
Summary: In this study, vortex induced vibrations of a pivoted cylinder with finite height were numerically investigated using a mathematical model. Various parameters were considered and results on solid body trajectories, amplitude of oscillations, hydrodynamic force coefficients, wake structure, and details on vortex shedding near the cylinder were presented. The numerical results showed good agreement with established VIV systems, suggesting potential for future research in related VIV systems at larger Reynolds numbers.
Article
Mechanics
Hadrien Calmet, Kiao Inthavong, Ambrus Both, Anurag Surapaneni, Daniel Mira, Beatriz Egukitza, Guillaume Houzeaux
Summary: This study used high-fidelity simulations to predict the dispersion of droplets produced by coughing, showing that droplets with small diameters mainly contribute to the risk of respiratory transmission.
Article
Biochemical Research Methods
Alfonso Santiago, Constantine Butakoff, Beatriz Eguzkitza, Richard A. Gray, Karen May-Newman, Pras Pathmanathan, Vi Vu, Mariano Vazquez
Summary: This study presents a model of the LV-LVAD system and a VVUQ plan based on ASME standards to ensure credible predictions. The simulation was validated using the SDSU cardiac simulator, and the numerical model was based on Alya. The VVUQ plan included risk analysis, verification stage, sensitivity analysis, and uncertainty quantification. The results showed correctness of the solution procedure and identified the most impactful inputs for the analysed quantities of interest. The simulations were computationally expensive but demonstrated the feasibility of stringent VVUQ according to ASME standards.
PLOS COMPUTATIONAL BIOLOGY
(2022)
Article
Computer Science, Interdisciplinary Applications
G. Houzeaux, R. M. Badia, R. Borrell, D. Dosimont, J. Ejarque, M. Garcia-Gasulla, V Lopez
Summary: This work presents an elastic computing methodology that adjusts the allocated resources to a simulation automatically based on the runtime measure of communication efficiency, resulting in efficient simulations.
COMPUTERS & FLUIDS
(2022)
Article
Pharmacology & Pharmacy
Hadrien Calmet, Damien Dosimont, David Oks, Guillaume Houzeaux, Brenda Vara Almirall, Kiao Inthavong
Summary: Targeted nasal drug delivery can be improved by adjusting spray parameters. This study investigated the effects of different values of six spray parameters on particle deposition. Sensitivity analysis showed that particle size significantly affected deposition in the olfactory and posterior regions, while spray device insertion angle had a significant impact on deposition in the anterior and middle regions. Machine learning models based on 384 cases provided accurate predictions despite the small sample dataset.
INTERNATIONAL JOURNAL OF PHARMACEUTICS
(2023)
Article
Mechanics
J. C. Cajas, I. Rodriguez, E. Salcedo, O. Lehmkuhl, G. Houzeaux, C. Trevino
Summary: The effect of aspect ratio on vortex induced vibrations (VIV) of a pivoted circular cylinder with different length-to-diameter ratios was studied. The study found that the aspect ratio influenced the oscillation amplitudes, synchronization region, and wake structures. At lower reduced velocities, steady symmetrical flow was obtained for cylinders with small aspect ratios, but became unstable at higher velocities.
Article
Computer Science, Interdisciplinary Applications
David Oks, Guillaume Houzeaux, Mariano Vazquez, Michael Neidlin, Cristobal Samaniego
Summary: This study evaluates the effect of TAVR commissural alignment on coronary perfusion and device performance using a computational fluid-structure interaction model.
COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE
(2023)
Article
Energy & Fuels
Abel Gargallo-Peiro, Gonzalo Revilla, Matias Avila, Guillaume Houzeaux
Summary: A novel approach for wind farm simulation is presented, featuring realignment and mesh adaptation. The method utilizes actuator discs to model turbines and combines a level-set-based simulation framework with an adaptation cycle. The results demonstrate the accuracy and efficiency of the proposed approach in simulating complex wind farm configurations.
Article
Computer Science, Interdisciplinary Applications
H. Calmet, K. Inthavong, H. Owen, D. Dosimont, O. Lehmkuhl, G. Houzeaux, M. Vazquez
Summary: CFD has shown great potential as a diagnostic tool in clinical trials, but overall statistical findings from large population samples are necessary for real clinical applications. This study compared a highly-resolved solution with lower resolution models to determine minimum modelling criteria for accurate respiratory flows in large-scale clinical applications. Results indicated that lower resolution models could achieve sufficient accuracy if mean flow was considered, and a stable transient result required data at least from the second respiration cycle. The study's findings offer guidance for future modelling efforts in clinical and engineering applications.
COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
(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)