Journal of Computational Physics最新文献

{"title":"A quantitative sampling method for elastic and electromagnetic sources","authors":"Xiaodong Liu ,&nbsp;Qingxiang Shi","doi":"10.1016/j.jcp.2025.114251","DOIUrl":"10.1016/j.jcp.2025.114251","url":null,"abstract":"<div><div>This study introduces an innovative sampling method for reconstructing elastic and electromagnetic wave sources from far-field patterns. We show that the proposed indicators in the form of integrals with full far field patterns are exactly the source functions. These results simultaneously establish the uniqueness of the inverse source problem and provide a theoretical justification for the sampling scheme. For practical implementation constraints involving sparse sensors and discrete frequencies, we formulate a stability estimation framework for discrete indicators. We have also proposed the indicators with partial far field patterns and proved their validity for providing the derivative information of the unknown sources. Numerical examples are presented to verify the accuracy and stability of the proposed quantitative sampling method.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114251"},"PeriodicalIF":3.8,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An efficient matrix-equivalent discrete fracture network model for variably-saturated flow in fractured porous media","authors":"Anis Younes","doi":"10.1016/j.jcp.2025.114260","DOIUrl":"10.1016/j.jcp.2025.114260","url":null,"abstract":"<div><div>Flow in fractured reservoirs is often controlled by a complex high-conductive fracture network. The dual-porosity model (DPM) and the discrete fracture-matrix model (DFM) are among the most widely used models for flow simulation in fractured media. The DPM gained high efficiency by replacing the fracture network by a continuum medium, but cannot be used for a disconnected network of fractures. The DFM model allows to treat explicitly the fractures but can suffer from low efficiency due the poor quality of meshes in the case of complex fracture networks. In this study, we propose an efficient matrix-equivalent discrete fracture network (MEDFN) model for unsaturated flow in fractured porous media. The main idea of the new model is to replace the matrix continuum by an equivalent low-permeable rectangular fracture network. Thus, the flow is solved on a global fracture network formed by the initial fracture network supplemented by the matrix-equivalent fracture network. The main advantages of the MEDFN model are: (<em>i</em>) it accurately accounts for the effect of individual fractures by explicitly considering the high-conductive fracture network, (<em>ii</em>) the role of the low-permeable matrix is taking into account through the added equivalent fracture network and (<em>iii</em>) the new model is highly efficient since the flow is solved on the set of 1D linear elements forming the global network.</div><div>The MEDFN model is developed here for the nonlinear variably-saturated flow in fractured porous media using the finite volume (FV) spatial discretization method and high-order time integration methods, via the method of lines (MOL). Numerical experiments are performed to validate the proposed MEDFN model and to assess its efficiency and accuracy, as compared to COMSOL and to the mixed finite element discrete fracture-matrix model (MFE-DFM), for the simulation of flow in fractured reservoirs under saturated and unsaturated conditions.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114260"},"PeriodicalIF":3.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An a posteriori time error indicator for adaptive flow solvers","authors":"Javad Sekhavati ,&nbsp;Ramon Codina ,&nbsp;Joan Baiges ,&nbsp;Ignacio Martínez-Suárez","doi":"10.1016/j.jcp.2025.114258","DOIUrl":"10.1016/j.jcp.2025.114258","url":null,"abstract":"<div><div>This study introduces a novel a posteriori time error indicator applied to a finite element flow solver. The proposed approach integrates stabilized finite element techniques in space and backward differentiation formula (BDF) schemes in time, adjusting time step sizes dynamically in unsteady flow simulations. The developed time error indicator and time adaptivity algorithm encompass monolithic and fractional step algorithms. In the case of fractional step algorithms, an additional term is incorporated in the error indicator to account for the error caused by the splitting. A series of numerical examples are presented to validate the reliability and robustness of the time error indicator across benchmark problems involving incompressible and isentropic compressible flows.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114258"},"PeriodicalIF":3.8,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fourth order mixed compact finite difference scheme for biharmonic equations","authors":"Kejia Pan ,&nbsp;Jin Li ,&nbsp;Zhilin Li ,&nbsp;Hongling Hu","doi":"10.1016/j.jcp.2025.114254","DOIUrl":"10.1016/j.jcp.2025.114254","url":null,"abstract":"<div><div>A fourth order mixed compact finite difference scheme for solving both two and three dimensional biharmonic equations with essential boundary conditions is presented in this paper. The key ideas of the new algorithm include an augmented intermediate variable and elegant high order treatment of the Neumann/Robin boundary conditions based on recent work on high order compact scheme [SIAM J. Sci. Comput., 45 (2023), pp. A646–A674]. Compared with existing schemes, the new method is more compact, natural and simpler in terms of discretization, and more importantly, the condition number of the coefficient matrix is of <span><math><mrow><mi>O</mi><mo>(</mo><msup><mi>h</mi><mrow><mo>−</mo><mn>2</mn></mrow></msup><mo>)</mo></mrow></math></span> instead of the usual <span><math><mrow><mi>O</mi><mo>(</mo><msup><mi>h</mi><mrow><mo>−</mo><mn>4</mn></mrow></msup><mo>)</mo></mrow></math></span>. Using the discrete Green function and energy analysis, the high order convergence has been proved. The proposed high order compact scheme has been validated through nontrivial numerical examples. Additionally, the proposed method has been applied to solve some nonlinear biharmonic equations.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114254"},"PeriodicalIF":3.8,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144770879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fully coupled implicit hydro-mechanical multiphase flow simulation in deformable porous media using DEM","authors":"Quanwei Dai ,&nbsp;Kang Duan ,&nbsp;Chung-Yee Kwok","doi":"10.1016/j.jcp.2025.114253","DOIUrl":"10.1016/j.jcp.2025.114253","url":null,"abstract":"<div><div>Knowledge of the underlying mechanisms of multiphase flow dynamics in porous media is crucial for optimizing subsurface engineering applications like geological carbon sequestration. However, studying the micro-mechanisms of multiphase fluid–grain interactions in the laboratory is challenging due to the difficulty in obtaining mechanical data such as force and displacement. Traditional discrete element method models coupled with pore networks offer insights into these interactions but struggle with accurate pressure prediction during pore expansion from fracturing and efficient simulation during the slow drainage of compressible fluids. To address these limitations, we develop an advanced two-way coupled hydro-mechanical discrete element method model that accurately and efficiently captures fluid–fluid and fluid–grain interactions in deformable porous media. Our model integrates an unconditionally stable implicit finite volume approach, enabling significant timesteps for advancing fluids. A pressure-volume iteration scheme dynamically balances injection-induced pressure buildup with substantial pore structure deformation, while flow front-advancing criteria precisely locate the fluid–fluid interface and adaptively refine timesteps, particularly when capillary effects block potential flow paths. The model is validated against benchmark Hele-Shaw experiments in both rigid and deformable porous media, providing quantitative insights into the micro-mechanisms governing multiphase flow. For the first time, grain-scale inputs such as viscous and capillary pressures, energies, contact forces, and flow resistances are utilized to provide a detailed understanding of micro-scale fluid–fluid and fluid–grain flow patterns and their transitions.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114253"},"PeriodicalIF":3.8,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A coupled volume-of-fluid/pressure-correction method for incompressible gas-liquid flows with phase change","authors":"Michael S. Dodd ,&nbsp;Pablo Trefftz-Posada ,&nbsp;Antonino Ferrante","doi":"10.1016/j.jcp.2025.114252","DOIUrl":"10.1016/j.jcp.2025.114252","url":null,"abstract":"<div><div>We have developed a pressure-correction method, FastP<span><math><msup><mrow></mrow><mo>*</mo></msup></math></span>PC, for simulating incompressible gas-liquid flows with phase change, as an extension of FastP<span><math><msup><mrow></mrow><mo>*</mo></msup></math></span>. The gas-liquid interface is captured using a volume-of-fluid (VoF) method that is mass conserving also in the presence of evaporation and condensation. The method relies on a divergence-free extrapolation of the gas- and liquid-phase velocity fields in the vicinity of the interface between the two fluids. This allows using any VoF algorithm for incompressible flows while the resulting numerical solution automatically keeps the boundedness and conservation properties of the chosen VoF method. The approach also has the advantage of not requiring the solution of an additional Poisson or Helmholtz equation for the entire computational domain at each time step, which is often encountered in existing methods. The results show that the interface position is computed with a spatial accuracy between first and second order. The method also applies a normal-probe approach to compute the mass flux due to phase change with second-order accuracy. Furthermore, we present a novel discretization of the vapor-species mass conservation equation for interfacial flows with phase change and a new numerical method to solve the energy equation. The flow solver maintains a sharp representation of the interface in the sense that jumps in velocity, pressure, temperature gradient, and VoF function occur over only one computational cell. A new analytical solution for verification is presented for a one-dimensional Stefan flow problem with multi-component gas phase. We apply the method to a three-dimensional evaporating droplet in quiescent conditions and demonstrate that the droplet diameter follows the <span><math><msup><mi>D</mi><mn>2</mn></msup></math></span>-law and that the solution approaches the analytical asymptotic value of the Sherwood number.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114252"},"PeriodicalIF":3.8,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinear model reduction with Neural Galerkin schemes on quadratic manifolds","authors":"Philipp Weder ,&nbsp;Paul Schwerdtner ,&nbsp;Benjamin Peherstorfer","doi":"10.1016/j.jcp.2025.114249","DOIUrl":"10.1016/j.jcp.2025.114249","url":null,"abstract":"<div><div>Leveraging nonlinear parametrizations for model reduction can overcome the Kolmogorov barrier that affects transport-dominated problems. In this work, we build on the reduced dynamics given by Neural Galerkin schemes and propose to parametrize the corresponding reduced solutions on quadratic manifolds. We show that the solutions of the proposed quadratic-manifold Neural Galerkin reduced models are locally unique and minimize the residual norm over time, which promotes stability and accuracy. For linear problems, quadratic-manifold Neural Galerkin reduced models achieve online efficiency in the sense that prediction costs scale independently of the state dimension of the underlying full model. For nonlinear problems, we show that Neural Galerkin schemes allow using collocation points distinct from the full-model grid points for evaluating the residual function, which can be seen as a form of hyper-reduction. Numerical experiments with advecting waves and densities of charged particles in an electric field show that quadratic-manifold Neural Galerkin reduced models lead to orders of magnitude speedups compared to full models.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114249"},"PeriodicalIF":3.8,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simple and efficient second-order immersed-boundary method for the incompressible Navier–Stokes equations","authors":"Paolo Luchini ,&nbsp;Davide Gatti ,&nbsp;Alessandro Chiarini ,&nbsp;Federica Gattere ,&nbsp;Marco Atzori ,&nbsp;Maurizio Quadrio","doi":"10.1016/j.jcp.2025.114245","DOIUrl":"10.1016/j.jcp.2025.114245","url":null,"abstract":"<div><div>An immersed-boundary method for the incompressible Navier–Stokes equations is presented. It employs discrete forcing for a sharp discrimination of the solid-fluid interface, and achieves second-order accuracy, demonstrated in examples with highly complex three-dimensional geometries. The method is implicit, meaning that the point in the solid which is nearest to the interface is accounted for implicitly, which benefits stability and convergence properties; the correction is also implicit in time (without requiring a matrix inversion), although the temporal integration scheme is fully explicit. The method stands out for its simplicity and efficiency: when integrated with second-order finite differences, only the weight of the center point of the Laplacian stencil in the momentum equation is modified, and no corrections for the continuity equation and the pressure are required. The immersed-boundary method, its performance and its accuracy are first verified on simple problems, and then put to test on a simple laminar, two-dimensional flow and on two more complex examples: the turbulent flow in a channel with a sinusoidal wall, and the flow in a human nasal cavity, whose extreme anatomical complexity mandates an accurate treatment of the boundary.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114245"},"PeriodicalIF":3.8,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pressure-based lattice Boltzmann method for mixture model equations of multiphase flow","authors":"Zikang Hao ,&nbsp;Limin Wang","doi":"10.1016/j.jcp.2025.114247","DOIUrl":"10.1016/j.jcp.2025.114247","url":null,"abstract":"<div><div>The pressure-based finite volume method (FVM) is insufficient for accurately solving multiphase mixture models due to its failure to conserve mass at dispersed interfaces. To address this limitation, a new pressure-based lattice Boltzmann method for mixture model equations (PLBM-MME) of multiphase flow has been proposed. Numerical results demonstrate that PLBM-MME successfully incorporates slip velocity, aligning with the diffusion stress caused by phase slip in mixture equations. By integrating a density-decoupled solution with volume fraction equation for secondary phase, the proposed method captures Kelvin-Helmholtz instability in lock-exchange flows without relying on Boussinesq approximation, as well as Rayleigh-Taylor instability while adhering to mass conservation more effectively than FVM. PLBM-MME has significant advantages over traditional FVM in conservation properties in discontinuity of density, suggesting it to be a promising computational strategy for accurately simulating complex multiphase flows.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114247"},"PeriodicalIF":3.8,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A node conservative cell-centered finite volume method for solving multidimensional Euler equations over general unstructured grids","authors":"Vincent Delmas ,&nbsp;Raphaël Loubère ,&nbsp;Pierre-Henri Maire","doi":"10.1016/j.jcp.2025.114246","DOIUrl":"10.1016/j.jcp.2025.114246","url":null,"abstract":"<div><div>We are interested in the numerical simulation of hypersonic flows around vehicles characterized by complex geometry. As a first step to move in this direction, we present a robust and accurate cell-centered Finite Volume (FV) method for solving the three-dimensional compressible Euler equations over general unstructured grids. This FV approach relies on a novel positivity-preserving discretization of the multidimensional Euler equations, which leverages a partitioning of cell faces into subfaces impinging at the nodes. The subface flux approximation is derived from an approximate Riemann solver, which incorporates not only the mean values of the cells adjacent to the subface but also the velocity of the node from which the subface originates. The projection of the nodal velocity onto the unit normal vector of the subface can be interpreted as a parameter in this Riemann solver. Consequently, the resulting subface flux is not unique, leading to a lack of conservation in the classical sense. Conservation is restored by ensuring that the subface fluxes around a node sum to zero, which determines the nodal velocity. This innovative multipoint flux approximation approach seems to eliminate the numerical pathologies commonly encountered in classical face-based FV formulations. The space and time second-order extension of this FV approach is classically deduced by means of a monotonic piecewise linear reconstruction. The robustness and accuracy of this novel numerical method are assessed against various demanding representative test cases in 2D and 3D.</div></div>","PeriodicalId":352,"journal":{"name":"Journal of Computational Physics","volume":"539 ","pages":"Article 114246"},"PeriodicalIF":3.8,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}