Article
Computer Science, Interdisciplinary Applications
Jeanne Joachim, Carole-Anne Daunais, Valerie Bibeau, Luca Heltai, Bruno Blais
Summary: In this study, a parallel immersed boundary strategy using Nitsche's method (NIB) is proposed to impose boundary conditions on a fluid. The NIB method is validated and compared with other methods in well-established test cases. The versatility of the NIB method is demonstrated by simulating a mixing rig with two off-centered impellers. The software and simulation files used in this study are available in the public domain for reproducibility.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Engineering, Marine
Zhao-Li Tian, A-Man Zhang, Yun-Long Liu, Shi-Ping Wang
Summary: In this paper, the penalty immersed boundary method is improved for resolving transient fluid-solid interaction problems, with the Eulerian finite-element method chosen as the fluid solver to ensure correct results for discontinuous problems. The simulated results are compared with experiments, showing good agreements.
Article
Engineering, Multidisciplinary
Narendra S. Nanal, Scott T. Miller, Jesse D. Thomas, Lucy T. Zhang
Summary: This study presents a computational framework for simulating shell structures interacting with fluids using the immersed approach. The approach captures the complex movement and motion of thin structures and allows non-intrusive coupling of independent fluid and shell finite element solvers. The method projects the shell structure to create a volumetric structure, enabling accurate and realistic loading and geometry.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Mathematics, Interdisciplinary Applications
Seok-Jin Park, Younghwan Yang, Junhong Jo, Tae-Rin Lee
Summary: In this study, a new method is proposed to simulate fluid-cell interactions by coupling the immersed finite element method with the spring network model. Successful simulation of cell transport and prediction of plasma skimming effect validate the effectiveness of the proposed method.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Jae H. Lee, Boyce E. Griffith
Summary: The immersed boundary (IB) method is a non-body conforming approach to fluid structure interaction (FSI). This study systematically investigates the effect of the choice of regularized delta function in several fluid-structure interaction benchmark tests using the immersed finite element/difference (IFED) method. The results show that the choice of kernel function, kernel width, and relative mesh widths of the Lagrangian and Eulerian discretizations all have an impact on the accuracy of the methodology.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Computer Science, Interdisciplinary Applications
David R. Wells, Ben Vadala-Roth, Jae H. Lee, Boyce E. Griffith
Summary: The IFED method is a computational approach for modeling fluid-structure interactions using finite element and finite difference techniques. This paper presents numerical and computational analyses of the effects of replacing the projection matrices in the force projection and IFED coupling operators with diagonal approximations. The results show that lumped mass matrices derived from nodal quadrature rules can be used with the IFED method, unlike standard FE methods.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Thermodynamics
Farhad A. Amiri, Junfeng Zhang
Summary: The paper introduces an immersed membrane method for simulating mass transfer across flexible semipermeable membranes, effectively addressing technical challenges. By replacing the sharp membrane interface with an immersed membrane layer, the mass transfer process can be solved using a uniform numerical scheme. Validation and demonstration simulations show that the method accurately represents the membrane effect on mass transfer.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Computer Science, Interdisciplinary Applications
Jonathan Boustani, Michael F. Barad, Cetin C. Kiris, Christoph Brehm
Summary: A parallel computational method is presented and validated for simulating fluid-structure interaction problems involving large deformations of thin shell structures. The method is tested for canonical simulation based test cases and experimental fluid-structure interaction problems, as well as applied to the inflation of a spacecraft parachute in supersonic flow conditions resembling the upper Martian atmosphere, showing good agreement with experimental data.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Engineering, Marine
Freddy Alejandro Portillo Morales, Ricardo Serfaty, Joao Marcelo Vedovotto, Aldemir Cavallini Jr, Millena Martins Villar, Aristeu da Silveira Neto
Summary: This paper presents the mathematical modeling and numerical simulations of fluid-structure interaction problems using Cartesian block-structured mesh, Finite Volume Method for the fluid domain, and Immersed Boundary Method for the solid-fluid interface. The simulations focus on a pipeline system in the oil and gas industry, predicting the surface response using machine learning.
Article
Engineering, Chemical
Maryam Askarishahi
Summary: The researchers developed a stable OpenFOAM solver for Immersed Boundary Method and implemented a fluid-structure interaction (FSI) coupling method to accurately calculate the fluid forcing term and particle velocity. The solver was validated for fixed and moving bodies, and the accuracy of various FSI schemes and their impact on solid and fluid flow behavior in a viscous flow were evaluated. The study also analyzed the dynamic flow behavior of colliding particles and predicted the effective restitution coefficient of particles in a viscous flow.
ADVANCED POWDER TECHNOLOGY
(2023)
Article
Engineering, Chemical
Sina Hassanzadeh Saraei, Bernhard Peters
Summary: Although CFD-DEM simulations can accurately predict long-range hydrodynamic interaction, they face challenges in capturing lubrication effects due to insufficient mesh resolution for close distance particle interactions. To address this, we used a variant of Immersed Boundary method in our CFD solver for fully resolved simulations. We also developed a second-order boundary layer reconstruction approach to improve accuracy. Additionally, we investigated the treatment of shared cells between particles and the impact of mesh resolution and time step size on force calculation accuracy, finding a specific ratio range for correct short-range hydrodynamic interaction capture.
Article
Engineering, Multidisciplinary
Ze Zhao, Jinhui Yan
Summary: This paper presents an enriched immersed boundary method (EIBM) to address the challenge of simultaneously maintaining accuracy of resolving boundary conditions and mesh flexibility in interface-coupled multi-physics problems. The method enhances the accuracy of the fluid-solid interface by enriching the degrees of freedom and resolves all the physical unknowns on the background mesh. The EIBM is evaluated through a set of examples and demonstrates its efficacy in conjugate heat transfer.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Mathematics, Interdisciplinary Applications
Marton Petoe, Mahan Gorji, Fabian Duvigneau, Alexander Duester, Daniel Juhre, Sascha Eisentraeger
Summary: Code verification is crucial for finite element applications, especially for non-standard approaches. In this article, the method of manufactured solutions (MoMS) is explored to derive closed-form reference solutions for immersed boundary problems. Various approaches are proposed for constructing manufactured solutions, enabling code verification without weak boundary conditions and keeping the simulation complexity low.
COMPUTATIONAL MECHANICS
(2023)
Article
Engineering, Multidisciplinary
Junqi Zhang, Mi Zhao, Sascha Eisentraeger, Xiuli Du, Chongmin Song
Summary: This article introduces a parallel asynchronous explicit solver widely used in structural dynamics problems. It reduces computational costs by assigning different time step sizes to different parts of the mesh and improves performance and accuracy through the use of a balanced octree and a special polyhedral element formulation.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Physics, Mathematical
D. Geyer, S. Ziegler, A. Sukhov, M. Hubert, A. -s. Smith, O. Aouane, P. Malgaretti, J. Harting
Summary: The performance of microswimmers, whether individually or collectively, is greatly influenced by the hydrodynamic coupling between their components and themselves. In this study, we conducted numerical simulations using the lattice Boltzmann method (LBM) to investigate the behavior of a single microswimmer and a pair of microswimmers. Our numerical approach involved the discretization of microswimmers using Lagrange polynomials, while the lattice Boltzmann method described the dynamics of the surrounding fluid. We observed the onset of collective effects and an overall velocity increment of clusters of swimmers in our data.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2023)
Article
Instruments & Instrumentation
Vincent Serantoni, Franck Jourdan, Herve Louche, Ariane Sultan
Summary: This study proposes a protocol for generating skin temperature oscillations and quantifying them using infrared cameras and spectral analysis in a clinical setting. Results showed that a 6-minute walking exercise increased thermoregulation activity beneath the plantar foot sole.
QUANTITATIVE INFRARED THERMOGRAPHY JOURNAL
(2021)
Article
Mathematical & Computational Biology
Thierry Mignon, Simon Mendez
Summary: At low shear rates, studying the dynamics of a single red blood cell in shear flow involves complex behaviors that require mathematical models and techniques from algebraic geometry. By rewriting existing models and determining steady-state solutions, a better understanding of the transition between different motions of red blood cells can be achieved.
MATHEMATICAL MODELLING OF NATURAL PHENOMENA
(2021)
Article
Biochemical Research Methods
Pierre Taraconat, Jean-Philippe Gineys, Damien Isebe, Franck Nicoud, Simon Mendez
Summary: Numerical results emphasize the link between cell flow-induced rotation and error in measured volume, leading to the development of two methods to identify and reject rotation-associated pulses. Detecting and rejecting rotation-induced pulses yield results comparable to hydrodynamical focusing, the gold standard implementation of the Coulter principle.
Article
Multidisciplinary Sciences
Thomas Puiseux, Anou Sewonu, Ramiro Moreno, Simon Mendez, Franck Nicoud
Summary: A numerical approach for simulating time-resolved 3D phase-contrast MRI under realistic flow conditions is presented. The Navier-Stokes and Bloch equations are solved with specific strategies to reduce computational cost. The simulated results compare favorably with experimental data.
Article
Physics, Fluids & Plasmas
P. Matteoli, F. Nicoud, S. Mendez
Summary: This study compares the impact of internal fluid viscosity and membrane viscosity on tank-treading red blood cells using numerical simulations supported by experimental data. It is found that both viscosities decrease the tank-treading frequency and have moderate effects on the cell deformation. Furthermore, direct inference of membrane viscosity as a function of shear rate is proposed based on the comparison between simulations and experiments.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Acoustics
Yunyun Sun, Florian Vixege, Khuram Faraz, Simon Mendez, Franck Nicoud, Damien Garcia, Olivier Bernard
Summary: In this article, a numerical framework for generating clinical-like color Doppler imaging (CDI) is presented. Synthetic blood vector fields and realistic clutter artifacts are simulated for evaluating and improving the quality of Doppler imaging techniques.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2022)
Article
Engineering, Biomedical
Alain Berod, Christophe Chnafa, Simon Mendez, Franck Nicoud
Summary: Numerical computations of hemodynamics inside intracranial aneurysms treated by endovascular braided devices such as flow-diverters contribute to understanding and improving such treatment procedures. Nevertheless, these simulations yield high computational and meshing costs due to the heterogeneity of length scales between the dense weave of the fine struts of the device and the arterial volume.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2022)
Article
Engineering, Biomedical
Florian Vixege, Alain Berod, Pierre-Yves Courand, Simon Mendez, Franck Nicoud, Philippe Blanc-Benon, Didier Vray, Damien Garcia
Summary: Three-dimensional intraventricular vector flow mapping (3D-iVFM) is a method for observing the velocity vector fields of blood flow in the left ventricular cavity through three-dimensional reconstruction. By using a clinical triplane echocardiographic mode, 3D-iVFM is able to recover three-component velocity vector fields in the entire ventricular volume. Our results indicate that 3D-iVFM can accurately estimate the full-volume information of left intraventricular hemodynamics and decipher the dynamics of the intraventricular vortex during systole.
PHYSICS IN MEDICINE AND BIOLOGY
(2022)
Article
Radiology, Nuclear Medicine & Medical Imaging
Morgane Garreau, Thomas Puiseux, Solenn Toupin, Daniel Giese, Simon Mendez, Franck Nicoud, Ramiro Moreno
Summary: This study evaluated hemodynamic markers obtained by accelerated GRAPPA and compressed sensing 4D flow MRI sequences under complex flow conditions. The results showed similar hemodynamic patterns between MRI and computational fluid dynamics simulations, with larger discrepancies near the boundary walls. MRI scans tended to overestimate velocity profiles and peak velocities, but showed good agreement for flow rates. Computational fluid dynamics simulations are a useful tool to assess these differences, but are sensitive to modeling parameters.
MAGNETIC RESONANCE IN MEDICINE
(2022)
Article
Mechanics
Franck Jourdan, Jonaz Vasquez-Villegas, Rania Abdel Rahman El Anwarl, Simon Le Floc'h, Christiane Wagner-Kocher
Summary: This article aims to understand the principal strains distribution in inflation test for circular isotropic soft membranes through analytical, numerical, and experimental investigations. A semi-analytical model (SAM) is developed to provide a simple and original solution for the deformation and stresses during the test. Experimental tests and numerical simulations using a 3D finite element model (FEM) are conducted to evaluate the SAM. The results show that the strain calculated by the SAM follows the pattern of the circumferential strain obtained by the FEM up to a certain distance from the center of the disk.
MECHANICS RESEARCH COMMUNICATIONS
(2023)
Article
Engineering, Biomedical
Franck Nicoud
Summary: An adjoint-based methodology is proposed to compute the gradient of outcomes in the coagulation cascade mathematical models. The method is validated using a simple case involving 3 species and further applied to a complex model with 34 species and 45 reactions. The results show that the method produces consistent gradient estimates at a lower computational cost compared to the finite differences approximation.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Alain Berod, Fernando Mut, Juan Cebral, Simon Mendez, Christophe Chnafa, Franck Nicoud
Summary: The study applies a heterogeneous model developed by Berod et al to evaluate the hemodynamic effects of endovascular prostheses on cerebral aneurysms. The model shows good agreement with the actual treatment outcomes and successfully reproduces the jetting-type flows generated downstream of the struts.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2023)
Article
Mechanics
S. Blanchard, N. Odier, L. Gicquel, B. Cuenot, F. Nicoud
Summary: In the framework of wall-modeled large-eddy simulation (WMLES), the static Smagorinsky model predicts efficiently the wall shear stress, while more advanced static models like WALE or Sigma fail in this aspect. Smagorinsky is known to be too dissipative in the bulk flow and purely sheared flows, whereas the other models are better suited for near-wall flows.
Article
Computer Science, Interdisciplinary Applications
Tian Liang, Lin Fu
Summary: In this work, a new shock-capturing framework is proposed based on a new candidate stencil arrangement and the combination of infinitely differentiable non-polynomial RBF-based reconstruction in smooth regions with jump-like non-polynomial interpolation for genuine discontinuities. The resulting scheme achieves high order accuracy and resolves genuine discontinuities with sub-cell resolution.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Lukas Lundgren, Murtazo Nazarov
Summary: In this paper, a high-order accurate finite element method for incompressible variable density flow is introduced. The method addresses the issues of saddle point system and stability problem through Schur complement preconditioning and artificial compressibility approaches, and it is validated to have high-order accuracy for smooth problems and accurately resolve discontinuities.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Gabriele Ciaramella, Laurence Halpern, Luca Mechelli
Summary: This paper presents a novel convergence analysis of the optimized Schwarz waveform relaxation method for solving optimal control problems governed by periodic parabolic PDEs. The analysis is based on a Fourier-type technique applied to a semidiscrete-in-time form of the optimality condition, which enables a precise characterization of the convergence factor at the semidiscrete level. The behavior of the optimal transmission condition parameter is also analyzed in detail as the time discretization approaches zero.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jonas A. Actor, Xiaozhe Hu, Andy Huang, Scott A. Roberts, Nathaniel Trask
Summary: This article introduces a scientific machine learning framework that uses a partition of unity architecture to model physics through control volume analysis. The framework can extract reduced models from full field data while preserving the physics. It is applicable to manifolds in arbitrary dimension and has been demonstrated effective in specific problems.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Nozomi Magome, Naoki Morita, Shigeki Kaneko, Naoto Mitsume
Summary: This paper proposes a novel strategy called B-spline based SFEM to fundamentally solve the problems of the conventional SFEM. It uses different basis functions and cubic B-spline basis functions with C-2-continuity to improve the accuracy of numerical integration and avoid matrix singularity. Numerical results show that the proposed method is superior to conventional methods in terms of accuracy and convergence.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Timothy R. Law, Philip T. Barton
Summary: This paper presents a practical cell-centred volume-of-fluid method for simulating compressible solid-fluid problems within a pure Eulerian setting. The method incorporates a mixed-cell update to maintain sharp interfaces, and can be easily extended to include other coupled physics. Various challenging test problems are used to validate the method, and its robustness and application in a multi-physics context are demonstrated.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Xing Ji, Fengxiang Zhao, Wei Shyy, Kun Xu
Summary: This paper presents the development of a third-order compact gas-kinetic scheme for compressible Euler and Navier-Stokes solutions, constructed particularly for an unstructured tetrahedral mesh. The scheme demonstrates robustness in high-speed flow computation and exhibits excellent adaptability to meshes with complex geometrical configurations.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Alsadig Ali, Abdullah Al-Mamun, Felipe Pereira, Arunasalam Rahunanthan
Summary: This paper presents a novel Bayesian statistical framework for the characterization of natural subsurface formations, and introduces the concept of multiscale sampling to localize the search in the stochastic space. The results show that the proposed framework performs well in solving inverse problems related to porous media flows.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jacob Rains, Yi Wang, Alec House, Andrew L. Kaminsky, Nathan A. Tison, Vamshi M. Korivi
Summary: This paper presents a novel method called constrained optimized DMD with Control (cOptDMDc), which extends the optimized DMD method to systems with exogenous inputs and can enforce the stability of the resulting reduced order model (ROM). The proposed method optimally places eigenvalues within the stable region, thus mitigating spurious eigenvalue issues. Comparative studies show that cOptDMDc achieves high accuracy and robustness.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Andrea La Spina, Jacob Fish
Summary: This work introduces a hybridizable discontinuous Galerkin formulation for simulating ideal plasmas. The proposed method couples the fluid and electromagnetic subproblems monolithically based on source and employs a fully implicit time integration scheme. The approach also utilizes a projection-based divergence correction method to enforce the Gauss laws in challenging scenarios. Numerical examples demonstrate the high-order accuracy, efficiency, and robustness of the proposed formulation.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Junhong Yue, Peijun Li
Summary: This paper proposes two numerical methods (IP-FEM and BP-FEM) to study the flexural wave scattering problem of an arbitrary-shaped cavity on an infinite thin plate. These methods successfully decompose the fourth-order plate wave equation into the Helmholtz and modified Helmholtz equations with coupled conditions on the cavity boundary, providing an effective solution to this challenging problem.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
William Anderson, Mohammad Farazmand
Summary: We develop fast and scalable methods, called RONS, for computing reduced-order nonlinear solutions. These methods have been proven to be highly effective in tackling challenging problems, but become computationally prohibitive as the number of parameters grows. To address this issue, three separate methods are proposed and their efficacy is demonstrated through examples. The application of RONS to neural networks is also discussed.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Marco Caliari, Fabio Cassini
Summary: In this paper, a second order exponential scheme for stiff evolutionary advection-diffusion-reaction equations is proposed. The scheme is based on a directional splitting approach and uses computation of small sized exponential-like functions and tensor-matrix products for efficient implementation. Numerical examples demonstrate the advantage of the proposed approach over state-of-the-art techniques.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Sebastiano Boscarino, Seung Yeon Cho, Giovanni Russo
Summary: This work proposes a high order conservative semi-Lagrangian method for the inhomogeneous Boltzmann equation of rarefied gas dynamics. The method combines a semi-Lagrangian scheme for the convection term, a fast spectral method for computation of the collision operator, and a high order conservative reconstruction and a weighted optimization technique to preserve conservative quantities. Numerical tests demonstrate the accuracy and efficiency of the proposed method.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jialei Li, Xiaodong Liu, Qingxiang Shi
Summary: This study shows that the number, centers, scattering strengths, inner and outer diameters of spherical shell-structured sources can be uniquely determined from the far field patterns. A numerical scheme is proposed for reconstructing the spherical shell-structured sources, which includes a migration series method for locating the centers and an iterative method for computing the inner and outer diameters without computing derivatives.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
