Article
Multidisciplinary Sciences
Dong Xu, Jianing Liu, Yunfeng Wu, Chunning Ji
Summary: We propose a simple and generalized Discretized Immersed Boundary Method (DIBM) that significantly improves efficiency by discretizing the interpolation functions and reusing a predefined universal interpolation stencil. DIBM achieves speedup ratios of 30-40 or even higher compared to conventional Immersed Boundary Method (IBM), with estimated errors below 1%.
SCIENTIFIC REPORTS
(2023)
Article
Computer Science, Interdisciplinary Applications
Yadong Zeng, Amneet Pal Singh Bhalla, Lian Shen
Summary: This paper presents an adaptive implementation of the distributed Lagrange multiplier immersed boundary method for solving single- and multiphase fluid-structure interaction problems using multilevel collocated grids. The approach includes non-subcycling and subcycling time advancement schemes, demonstrating excellent momentum and mass conservation across different levels of grid hierarchy.
COMPUTERS & FLUIDS
(2022)
Article
Computer Science, Interdisciplinary Applications
Stephane Del Pino, Isabelle Marmajou
Summary: In this paper, an adaptive mesh refinement method for 2D multi-material compressible non-viscous flows in semi-Lagrangian coordinates is proposed. The method utilizes a local mesh adaptation procedure and a discrete metric field evaluation. The remapping method used is second-order accurate and its stability is proven. A multi-material treatment is proposed using a combination of local remeshing and interface reconstruction methods to minimize the creation of mixed cells and the diffusion of material interfaces. Numerical tests are provided to verify the validity and robustness of the method.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Engineering, Multidisciplinary
Zhengliang Liu, Fang-Bao Tian, Xingya Feng
Summary: This work presents an adaptive mesh refinement (AMR) method based on a hash table representation of octrees. The performance of the AMR framework with different data structures and strategies is analyzed using two complex geometries. Moreover, the proposed AMR framework is evaluated in computational fluid dynamics (CFD) applications using the immersed boundary-lattice Boltzmann method (IB-LBM). The results show significant reductions in computational time and benefits for 3D cases with larger numbers of nodes when using the hash table.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
S. Zaghi, F. Salvadore, A. Di Mascio, G. Rossi
Summary: This article presents a new high-performance ADAM library that uses adaptive mesh refinement and immersed boundary methods to solve complex fluid simulation problems. The library runs efficiently on modern GPU-accelerated supercomputers and has a highly modular structure, making it versatile for various CFD applications.
COMPUTERS & FLUIDS
(2023)
Article
Engineering, Mechanical
Pedro Ricardo C. Souza, Helio Ribeiro Neto, Millena Martins Villar, Joao Marcelo Vedovotto, Aldemir Ap Cavalini Jr, Aristeu Silveira Neto
Summary: In this study, the authors aim to solve incompressible fluid-structure interaction problems in multi-phase flows using a partitioned approach. They develop a three-dimensional, block-structured, adaptive mesh refinement (AMR) code called MFSim. The simulation uses a projection method for large eddy simulation (LES) of Navier-Stokes equations and a VOF-PLIC method with finite volume discretization. The results show good agreement with experimental data.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Multidisciplinary
S. Eisentrager, J. Eisentrager, H. Gravenkamp, C. G. Provatidis
Summary: This article comprehensively discusses the construction and performance assessment of versatile transition elements for applications in dynamics, focusing on the use of special shape function construction to achieve diagonalization of the mass matrix.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Engineering, Marine
Kaustubh Khedkar, Amneet Pal Singh Bhalla
Summary: In this study, a novel MPC-integrated multiphase IB framework is proposed to compute the optimal energy-maximizing control force by dynamically interacting with a numerical wave tank (NWT). The performance and adaptability of the MPC-integrated multiphase IB solver are validated through comparisons with LPT-based solvers and simulations under different sea conditions.
Article
Thermodynamics
Leandro J. L. Stival, Joshua R. Brinkerhoff, Joao Marcelo Vedovotto, Fernando Oliveira de Andrade
Summary: This study applies large eddy simulation (LES) and immersed boundary (IB) method to investigate the flow around wind turbines and validates the results. The research shows that there is a significant loss of kinetic energy in the near wake region of the wind turbine, but the results are similar to the literature in the far wake region.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Computer Science, Interdisciplinary Applications
Zihao Cheng, Anthony Wachs
Summary: We propose an immersed boundary/multi-relaxation time lattice Boltzmann method for particle-resolved simulation of particle-laden flows. The method handles the no-slip boundary condition using an explicit feedback immersed boundary method and employs a smoothed discrete delta function and a multi-relaxation time collision operator for improved stability and accuracy. The method is extended to adaptive quadtree/octree grids and implemented in the open-source software Basilisk, achieving high computational efficiency and accuracy in a variety of validation cases.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Michele Annese, Miguel A. Fernandez, Lucia Gastaldi
Summary: This paper introduces a class of semi-implicit coupling schemes for the numerical approximation of incompressible fluid-structure interaction problems. These schemes avoid strong coupling while maintaining stability and accuracy. The theoretical results are supported by numerical experiments.
IMA JOURNAL OF NUMERICAL ANALYSIS
(2023)
Article
Computer Science, Interdisciplinary Applications
Vignesh Saravanan, Hanahchim Choung, Soogab Lee
Summary: This article proposes a hybrid adaptive mesh refinement algorithm for the immersed boundary method combination, aiming to achieve algorithmic simplicity and computational efficiency while reducing computational time by optimizing cell distribution. It introduces local near immersed boundary refinement to avoid computational complexity and demonstrates the effectiveness in steady and transient flows.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
(2022)
Article
Computer Science, Interdisciplinary Applications
Nathan Vaughn, Vikram Gavini, Robert Krasny
Summary: TAGI is a real-space computational method for all-electron Kohn-Sham Density Functional Theory that uses specialized Green Iteration and treecode acceleration to speed up convergence, with various techniques to improve efficiency and accuracy in energy calculations for atoms and small molecules.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
Yuchen Yang, Xinyu Qi, Zhenming Wang, Jianming Liu, Ning Zhao
Summary: In this paper, a parallelised adaptive hierarchical Cartesian-based immersed boundary methodology is developed for high Reynolds number compressible flow. The methodology includes automatic grid generation, immersed boundary method, parallel strategy, and adaptive mesh refinement. Testing on transonic and supersonic flows in different dimensions shows good performance and robustness of the method.
INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS
(2022)
Article
Engineering, Aerospace
Zichen Zhao, Haibin Shang, Chengliang Liu, Shuchen Xiao
Summary: This paper investigates the rapid optimization of a landing trajectory on an arbitrarily shaped asteroid. It proposes a method to convert the nonlinearity of the gravitational field into an equivalent convex version and uses a two-step convex optimization technique to generate the optimal trajectory. The method demonstrates its strength and correctness through theoretical analyses and numerical simulations.
JOURNAL OF SPACECRAFT AND ROCKETS
(2023)
Article
Engineering, Multidisciplinary
Tokimasa Shimada, Koji Nishiguchi, Rahul Bale, Shigenobu Okazawa, Makoto Tsubokura
Summary: The proposed monolithic fluid-structure interaction method utilizes a cell-centered finite volume formulation in the Eulerian description and Lagrangian marker particles in the solid region. By avoiding neighboring particle search, the approach shows sharper interfaces and more accurate numerical results in numerical examples.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(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
Aaron Barrett, Aaron L. Fogelson, Boyce E. Griffith
Summary: A new discretization approach for advection-diffusion problems with Robin boundary conditions on complex domains is presented, based on second-order cut cell finite volume methods. The method demonstrates second-order accuracy in various norms and the ability to convert chemical species across moving boundaries.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Rahul Bale, Akiyoshi Iida, Masashi Yamakawa, ChungGang Li, Makoto Tsubokura
Summary: The dose-response model is commonly used for quantifying the risk of airborne diseases like COVID-19, but not in the numerical simulations of droplet dispersion. This study develops a framework for evaluating the probability of infection in droplet dispersion simulations using the dose-response model, considering the higher transmissibility of variant strains and the effect of vaccination.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Biomedical
Dan Lior, Charles Puelz, Colin Edwards, Silvana Molossi, Boyce E. Griffith, Ravi K. Birla, Craig G. Rusin
Summary: This paper presents a semi-automatic method for constructing volumetric models of the aortic valve using computed tomography angiography images. The method uses manually selected samples of the aortic segmentation derived from the images to inform the model construction. Valve models for pediatric patients are created and simulation results show that the method produces functional valves that generate pressure and flow waveforms similar to clinical observations.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Biomedical
Jordan A. Brown, Jae H. Lee, Margaret Anne Smith, David R. Wells, Aaron Barrett, Charles Puelz, John P. Vavalle, Boyce E. Griffith
Summary: Transcatheter aortic valve replacement (TAVR) is a commonly used technique for aortic valve replacement, and computer modeling and simulation (CM&S) can assist in the design and approval process of TAVR devices. This study presents a computational fluid-structure interaction (FSI) model of TAVR using the immersed finite element-difference (IFED) method.
ANNALS OF BIOMEDICAL ENGINEERING
(2023)
Article
Computer Science, Hardware & Architecture
Kazuto Ando, Rahul Bale, ChungGang Li, Satoshi Matsuoka, Keiji Onishi, Makoto Tsubokura
Summary: The Fugaku supercomputer has revolutionized epidemiology and changed the behavior of the Japanese public by providing detailed analysis of COVID-19 transmission risks. Its innovative aerosol simulation method, utilizing a new CFD solver, allows for high-resolution simulations and rapid generation of digital twins representing various societal situations.
INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS
(2022)
Article
Engineering, Marine
Zhonglu Lin, Amneet Pal Singh Bhalla, Boyce E. Griffith, Zi Sheng, Hongquan Li, Dongfang Liang, Yu Zhang
Summary: This study investigates the effects of swimming styles and schooling on accelerating fish schools. It found that fish schools with lower wavelengths have higher propulsive efficiency, while fish schools with higher wavelengths have higher thrust. Additionally, the follower can benefit from the leader's performance by adjusting the phase difference, especially at higher wavelengths and close distances.
Article
Engineering, Biomedical
Aaron Barrett, Jordan A. Brown, Margaret Anne Smith, Andrew Woodward, John P. Vavalle, Arash Kheradvar, Boyce E. Griffith, Aaron L. Fogelson
Summary: Subclinical leaflet thrombosis (SLT) is a potentially serious complication in patients with bioprosthetic valve after aortic valve replacement, which is associated with increased risk of transient ischemic attacks and strokes. It may progress to clinical leaflet thrombosis and subsequent structural valve deterioration, affecting the durability of the replacement valve. Development of models to simulate leaflet thrombosis and predict patients at risk is crucial, and our approach combines fluid-structure interaction and a simplified thrombosis model for deposition along the moving leaflets. This advancement incorporates adhesion and feedback to fluid-structure interaction, providing valuable insights for modeling thrombosis.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Yadong Zeng, Han Liu, Qiang Gao, Ann Almgren, Amneet Pal Singh Bhalla, Lian Shen
Summary: We develop a consistent adaptive framework for simulating two-phase flows with adaptive mesh refinement. The framework greatly improves the accuracy and robustness for simulating high density ratio and high Reynolds number flows. The interface capturing level set method is coupled with the conservative form of the Navier-Stokes equations, and a multilevel reinitialization technique is applied for mass conservation.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
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
Mechanics
Li-Ming Chao, Amneet Pal Singh Bhalla, Liang Li
Summary: Both schooling behavior and burst-and-coast gait improve fish swimming performance, but the combined effect of these strategies is still unknown. Using the IBAMR software, we examine swimming speed and cost of transport efficiency by studying two pitching foils with different duty cycles. The findings suggest that stable schooling formation can only be maintained with similar and moderate duty cycles, which increase lateral movements but not swimming speed or efficiency. This research provides insights into fish behavior and valuable information for designing bio-inspired underwater robots.
THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
(2023)
Article
Engineering, Mechanical
Chung-Gang Li, Rahul Bale, WeiHsiang Wang, Makoto Tsubokura
Summary: In this study, a sharp interface immersed boundary method (IBM) for low Mach number viscous compressible flows is developed. The IBM utilizes a robust interpolation scheme to ensure stability for complex geometries with zero-thickness walls. By gradually reducing the order of interpolation near the wall, the method eliminates interaction between opposite sides in high order schemes. It also efficiently handles moving objects in compressible flows without requiring any special treatment. The method has been successfully applied to aerodynamic simulations, compression and expansion processes, and aeroacoustics simulations.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Computer Science, Interdisciplinary Applications
Ebrahim M. Kolahdouz, David R. Wells, Simone Rossi, Kenneth I. Aycock, Brent A. Craven, Boyce E. Griffith
Summary: This paper introduces a sharp-interface approach to simulating fluid-structure interaction involving flexible bodies. The approach combines the immersed Lagrangian-Eulerian (ILE) scheme with the immersed boundary (IB) method for better accuracy and flexibility. The paper presents the formulation, numerical approach, and validation of the algorithm through various benchmarks, including the modeling of a deformable blood clot.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Multidisciplinary Sciences
Rahul Bale, Chunggang Li, Hajime Fukudome, Saori Yumino, Akiyoshi Iida, Makoto Tsubokura
Summary: The use of masks is widely acknowledged to control respiratory virus transmission, but in certain environments where mask-wearing is not possible, the risk of virus transmission increases. To address this issue, researchers have developed a methodology to investigate the role of ventilation in reducing infection risk. They used a restaurant setting as an example and found that operating ventilation systems and increasing physical distance between individuals can significantly reduce the risk of infection. However, the effectiveness of these measures depends on the transmissibility of the airborne viruses.
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)