Article
Computer Science, Interdisciplinary Applications
Yanchuang Cao, Jun Liu, Dawei Chen
Summary: This work presents an explicitly-sparse representation for oscillatory kernels. It develops a wave atom based method to construct multilevel wave atom-like functions as a transform of the original nodal basis. The resulting system matrix is explicitly-sparse and computed explicitly, with further enhancement of sparsity via a-posteriori compression. Numerical results demonstrate the log-linear computational complexity with controllable accuracy. This representation is expected to lay ground to future work related to fast direct solvers and effective preconditioners for high frequency problems.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Dongwei Ye, Valeria Krzhizhanovskaya, Alfons G. Hoekstra
Summary: This work presents a data-driven surrogate model for efficient prediction of blood flow simulations on similar but distinct domains. The proposed model utilizes group surface registration to parameterize shapes and uses geometry information for hemodynamics prediction. The results demonstrate that the surrogate model has accuracy and efficiency in hemodynamics prediction and can be applied to real-time simulation and uncertainty quantification for complex patient-specific scenarios.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Junming Duan, Jan S. Hesthaven
Summary: This paper proposes a non-intrusive reduced-order modeling approach for time-dependent parametrized problems. It uses a convolutional autoencoder for dimensionality reduction and high-order dynamic mode decomposition for modeling time-dependent problems. Numerical tests show that the approach can accurately predict unseen full-order solutions.
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
Clemens Willers, Oliver Kamps
Summary: Modeling non-Markovian time series using the generalized Langevin equation (GLE) and Bayesian estimation is a promising approach in various fields. This study presents an efficient implementation of Bayesian estimation for GLE by using a piecewise constant approximation of the model's drift and diffusion functions. This method reduces the numerical cost and allows for the consideration of trend effects. The capabilities of the method and model are illustrated using an example from turbulence.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Rainald Lohner, Harbir Antil, Fernando Mut, Juan Cebral
Summary: This article introduces the use of adjoint solvers to obtain the sensitivity of clinical measures in aneurysms to incomplete boundary conditions and geometry, providing theoretical insights and computational tools. The authors derived sensitivities with respect to inflow and inflow position, and demonstrated the explicit expressions for underlying quantities in numerical experiments.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Anna Broms, Anna-Karin Tornberg
Summary: Rigid particles in a Stokesian fluid can experience strong lubrication resistance as particle gaps narrow. However, resolving these lubrication forces numerically can be computationally expensive and may lead to artificial particle collisions and overlaps. In this work, a barrier energy is used to efficiently represent non-overlap constraints between particles. By enforcing a zero barrier energy at the next time level, the method corrects for overlaps and obtains collision-free configurations. The effectiveness of the method is demonstrated in solving the mobility problem in Stokes flow and examining the collective order of particles in a background flow.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Tommaso Buvoli, Michael Minion
Summary: Parareal is a parallel-in-time algorithm that combines a coarse and fine propagator within a parallel iteration, leading to significantly reduced computational time compared to serial time-stepping methods. This paper explores the use of exponential integrators within the Parareal iteration to solve non-diffusive equations. Numerical experiments and linear analysis are conducted to evaluate the stability and convergence properties of the exponential Parareal iteration. Results demonstrate that the exponential Parareal methods offer improved time-to-solution compared to serial exponential integrators for certain non-diffusive equations.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
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
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
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
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
A. S. Moura, W. G. Facco
Summary: This research explores the application of differential forms in simulating wave propagation problems in three-dimensional domains and presents a novel formulation of the complex frequency-shifted perfectly matched layer. The directional incidence matrix is introduced to confine the unbounded domain, and an illustrative example is provided to validate the effectiveness of the model.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Daniel Johnson, Ronald Fedkiw
Summary: This paper discusses the discontinuity in collisions and its impact on numerical approaches. By handling the derivative of collision time, the paper allows for the smooth transition between collision and non-collision states, improving the reliability of numerical methods. Additionally, the paper points out the limitations of standard approaches in addressing this issue, mostly due to a lack of comprehensive understanding of the mathematical nature of the problem.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Stefano Boccelli, Willem Kaufmann, Thierry E. Magin, James G. McDonald
Summary: Max-entropy moment methods are used to model gases from continuum to rarefied conditions. This study applies a fourth-order maximum-entropy moment method to supersonic rarefied flows. It compares the maximum-entropy solutions to results obtained from the kinetic theory of gases and proposes an approximation for accurate estimates of wave speeds. The results show that the maximum-entropy method provides good accuracy and agreement with the kinetic theory in rarefied supersonic conditions.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yuxiao Wei, Jin Cheng, Robert Burridge, Jianliang Qian
Summary: In this paper, a novel Hadamard integrator is proposed for the self-adjoint time-dependent wave equation in an inhomogeneous medium. Through the use of the Gelfand-Shilov function and Kirchhoff-Huygens representation, the Hadamard integrator is constructed and derived in the Lagrangian formulation. The efficient implementation of the Hadamard integrator is achieved through the use of short-time ray tracing and fast algorithms, and it is successfully applied to time-dependent wave equations with various initial conditions. Numerical experiments validate the accuracy and performance of the proposed method.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yibo Fang, Lin Du, Chen He, Dakun Sun, Lijun Yang, Qingfei Fu, Xiaofeng Sun
Summary: A numerical framework based on the immersed boundary method is developed for global stability analysis of flow systems with complex geometry. The method is tested on two standard cases and applied to the stability analysis of a complex flow system with multiple objects, demonstrating its effectiveness.
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
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
Joan Bruna, Benjamin Peherstorfer, Eric Vanden-Eijnden
Summary: This study proposes a neural Galerkin scheme based on deep learning for numerically solving high-dimensional partial differential equations. The scheme generates training data through active learning, enabling simulation of phenomena and processes that traditional and other deep-learning-based solvers fail to handle.
JOURNAL OF COMPUTATIONAL PHYSICS
(2024)
