International Journal for Numerical Methods in Fluids最新文献

{"title":"A Filtered Embedded Weighted Compact Non-Linear Scheme for Hyperbolic Conservation Law","authors":"Xuan Liu,&nbsp;Yaobing Min,&nbsp;Jinsheng Cai,&nbsp;Yankai Ma,&nbsp;Zhen-Guo Yan","doi":"10.1002/fld.5366","DOIUrl":"https://doi.org/10.1002/fld.5366","url":null,"abstract":"<div>\u0000 \u0000 <p>In situations where a wide range of flow scales are involved, the non-linear scheme should be capable of both shock capturing and low-dissipation. Most of the existing Weighted Compact Non-linear Schemes (WCNS) are too dissipative and incapable of achieving fourth-order for the two smooth stencils located on the same side of a discontinuity due to the weight deviations and the defect of the weighting strategy. In this paper, a novel filtered embedded WCNS is introduced for complex flow simulations involving both shock and small-scale structures. To overcome the above deficiency of existing WCNS, a pre-discrete mapping function is proposed to filter the weight deviation out and amend the inappropriate weights to ideal weights in smooth regions. Meanwhile, the embedded process is also implemented by this function, which is utilized to improve the resolution of shock capturing in certain discontinuity distributions. The pre-discrete mapping function is also extended to the WENO framework. The approximate-dispersion-relation analysis indicates that the scheme with the mapping function has lower dispersion and dissipation error than the WCNS-JS, WCNS-Z, and WCNS-T schemes. Numerical results show that WCNS with the new non-linear weights captures discontinuities sharply without obvious oscillation, has a higher resolution than other non-linear schemes, and has an obvious advantage in capturing small-scale structures.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 5","pages":"736-764"},"PeriodicalIF":1.7,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Finite Element Method to Compute the Damping Rate and Frequency of Oscillating Fluids Inside Microfluidic Nozzles","authors":"Søren Taverniers,&nbsp;Svyatoslav Korneev,&nbsp;Christoforos Somarakis,&nbsp;Morad Behandish,&nbsp;Adrian J. Lew","doi":"10.1002/fld.5373","DOIUrl":"https://doi.org/10.1002/fld.5373","url":null,"abstract":"<div>\u0000 \u0000 <p>The computation of damping rates of an oscillating fluid with a free surface in which viscosity is small and surface tension high is numerically challenging. A typical application requiring such computation is drop-on-demand (DoD) microfluidic devices that eject liquid metal droplets, where accurate knowledge of the damping rates for the least-damped oscillation modes following droplet ejection is paramount for assessing jetting stability at higher jetting frequencies, as ejection from a nonquiescent meniscus can result in deviations from nominal droplet properties. Computational fluid dynamics (CFD) simulations often struggle to accurately predict meniscus damping unless very fine discretizations are adopted, so calculations are slow and computationally expensive. The faster alternative we adopt here is to compute the damping rate directly from the eigenvalues of the linearized problem. The presence of a surface tension term in Stokes or sloshing problems requires approximation of the meniscus displacements as well, which introduces additional complexity in their numerical solution. In this paper, we consider the combined effects of viscosity and surface tension, approximate the meniscus displacements, and construct a finite element method to compute the fluid's oscillation modes. We prove that if the finite element spaces satisfy a typical inf-sup condition, and the space of the meniscus displacements is a subset of the set of normal traces of the space of velocities, then the method is free of spurious modes with zero or positive damping rates. To construct numerical examples, we implement the method with Taylor-Hood elements for the velocity and pressure fields, and with continuous piecewise quadratic elements for the displacement of the meniscus. We verify the numerical convergence of the method by reproducing the solution to an analytical benchmark problem and two more complex examples with axisymmetric geometry. Remarkably, the spatial shape and temporal evolution (angular frequency and damping rate) of the set of least-damped oscillation modes are obtained in a matter of minutes, compared to days for a CFD simulation. The method's ability to quickly generate accurate estimates of fluid oscillation damping rates makes it suitable for integration into design loops for prototyping microfluidic nozzles.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 5","pages":"765-782"},"PeriodicalIF":1.7,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Numerical Simulation and Implicit Large-Eddy Simulation of Shock Train in Channel Flow Using High Order Optimised Targeted Essentially Non-Oscillatory Schemes","authors":"Agneev Roy,&nbsp;Sandeep Kumar,&nbsp;Somnath Ghosh","doi":"10.1002/fld.5372","DOIUrl":"https://doi.org/10.1002/fld.5372","url":null,"abstract":"<div>\u0000 \u0000 <p>Direct numerical simulation (DNS) and implicit large-eddy simulation (LES) of turbulent channel flows with isothermal walls, with and without shock trains, are performed using a recently proposed high-order optimized targeted essentially non-oscillatory (TENO) scheme. Mean flow and turbulence statistics are presented and compared with those previously obtained from DNS using a bandwidth-optimized weighted essentially non-oscillatory (WENO) scheme with limiter. It is observed that the TENO scheme performs better than the WENO scheme in predicting the mean flow and Reynolds stresses in these flows. The optimized TENO scheme used here is found to be very suitable for performing implicit LES on a relatively coarse grid.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 5","pages":"713-735"},"PeriodicalIF":1.7,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wetting and Drying Treatments With Mesh Adaptation for Shallow Water Equations Using a Runge–Kutta Discontinuous Galerkin Method","authors":"Camille Poussel,&nbsp;Mehmet Ersoy,&nbsp;Frédéric Golay","doi":"10.1002/fld.5365","DOIUrl":"https://doi.org/10.1002/fld.5365","url":null,"abstract":"<div>\u0000 \u0000 <p>This work is devoted to the numerical simulation of Shallow Water Equations involving dry areas, a moving shoreline and in the context of mesh adaptation. The space and time discretization using the Runge–Kutta Discontinuous Galerkin approach is applied to nonlinear hyperbolic Shallow Water Equations. Problems with dry areas are challenging for such methods. To counter this issue, special treatment is applied around the shoreline. This work compares three treatments, one based on Slope Modification, one based on p-adaptation and the last one based on eXtended Finite Element methods and mesh adaptation.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 5","pages":"692-712"},"PeriodicalIF":1.7,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Practical Approach to Time-Varying Inflow Simulation and the Influence on Intermittent Airflow Within Urban Street Canyons","authors":"Yunwei Zhang,&nbsp;Lushuang Zhao,&nbsp;Lizhi Jing,&nbsp;Haiyan Miao,&nbsp;Junwei Su,&nbsp;Zhaolin Gu","doi":"10.1002/fld.5362","DOIUrl":"https://doi.org/10.1002/fld.5362","url":null,"abstract":"<div>\u0000 \u0000 <p>Based on large eddy simulations, intermittent airflow within an urban street canyon was simulated. The practice of time-varying inflow conditions (TVIC) required a time series of inflow wind velocity, which could be collected on a varying curve of the moving averaged measured data. The influences of the time interval of the wind series and the varying trend (or molded line) between adjacent data on airflow within the street canyon were analyzed. The results showed that TVIC would result in larger average wind velocity and turbulence intensity than that simulated under steady inflow conditions (SIC). The simulated total vertical air exchanges under TVIC would be one order of magnitude higher than that simulated under SIC. Airflow characteristics within street canyons were influenced by the varying trends and the time intervals of the time-series inflow wind. Average vertical wind velocity and turbulent kinetic energy (TKE) simulated under the stepped varying trend was higher than that under the jagged varying trend. The shorter the time interval, the larger the TKE within the street canyon. Vertical air exchanges induced by turbulence (ACH′) at the roof level simulated under the stepped molded lines were twice that of the jagged molded line. Under the time interval of 30 s, the ACH′ was significantly increased, which was 2.558 times that simulated with a time interval of 1 min. Thus, the suggested practical approach for time-varying inflow simulations is to obtain time-series wind data with a time interval of 1 min or less, and the linearly molded line would be critical; for larger time intervals, reasonable molded lines would be required.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 5","pages":"676-691"},"PeriodicalIF":1.7,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143786797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solutions to Two- and Three-Dimensional Incompressible Flow Fields Leveraging a Physics-Informed Deep Learning Framework and Kolmogorov–Arnold Networks","authors":"Quan Jiang,&nbsp;Zhiyong Gou","doi":"10.1002/fld.5374","DOIUrl":"https://doi.org/10.1002/fld.5374","url":null,"abstract":"<div>\u0000 \u0000 <p>Physics-informed neural network (PINN) has become a potential technology for fluid dynamics simulations, but traditional PINN has low accuracy in simulating incompressible flows, and these problems can lead to PINN not converging. This paper proposes a physics-informed neural network method (KA-PINN) based on the Kolmogorov–Arnold Neural (KAN) network structure. It is used to solve two-dimensional and three-dimensional incompressible fluid dynamics problems. The flow field is reconstructed and predicted for the two-dimensional Kovasznay flow and the three-dimensional Beltrami flow. The results show that the prediction accuracy of KA-PINN is improved by about 5 times in two dimensions and 2 times in three dimensions compared with the fully connected network structure of PINN. Meanwhile, the number of network parameters is reduced by 8 to 10 times. The research results not only verify the application potential of KA-PINN in fluid dynamics simulations, but also demonstrate the feasibility of KAN network structure in improving the ability of PINN to solve and predict flow fields. This study can reduce the dependence on traditional numerical methods for solving fluid dynamics problems.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 4","pages":"665-673"},"PeriodicalIF":1.7,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Order Alternative Formulation of Weighted Essentially Non-Oscillatory Scheme With Minimized Dispersion and Controllable Dissipation for Compressible Flows","authors":"Wei-Gang Zeng,&nbsp;Lu Liu,&nbsp;Li-Jin Zeng,&nbsp;Jian-Hua Pan,&nbsp;Jun-Ping Yin,&nbsp;Yu-Xin Ren","doi":"10.1002/fld.5364","DOIUrl":"https://doi.org/10.1002/fld.5364","url":null,"abstract":"<div>\u0000 \u0000 <p>Following the proposition of the original AWENO (Alternative Formulation of Weighted Essentially Non-Oscillatory) FD (Finite Difference) scheme, we construct the new AMDCD FD scheme, an Alternative formulation of the linear FD scheme with Minimized Dispersion and Controllable Dissipation, in this article. Spectral analysis shows that the proposed AMDCD FD scheme can be more efficient in resolving smooth solutions due to the flexibility in controlling dissipation. To efficiently solve compressible flows with discontinuities, we further combined the proposed AMDCD FD scheme with the original AWENO FD scheme using a hybrid interpolation scheme, in which the optimized linear MDCD (Minimized Dispersion and Controllable Dissipation) interpolation scheme would be switched to the nonlinear WENO (Weighted Essentially Non-Oscillatory) type interpolation scheme gradually as the flow structures are in transition from smooth region towards the vicinity of discontinuities. Therefore, the resulting hybrid AWENO-AMDCD FD scheme is suitable for solving compressible flows with broad-scale flow structures and/or shock waves. A series of one-, two-, and three-dimensional compressible flow problems are numerically tested to demonstrate the accuracy, superior resolution, as well as the robustness of the proposed hybrid AWENO-AMDCD FD scheme.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 4","pages":"646-664"},"PeriodicalIF":1.7,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Augmented Lagrangian Trust-Region Method With Inexact Gradient Evaluations to Accelerate Constrained Optimization Problems Using Model Hyperreduction","authors":"Tianshu Wen,&nbsp;Matthew J. Zahr","doi":"10.1002/fld.5363","DOIUrl":"https://doi.org/10.1002/fld.5363","url":null,"abstract":"<div>\u0000 \u0000 <p>We present an augmented Lagrangian trust-region method to efficiently solve constrained optimization problems governed by large-scale nonlinear systems with application to partial differential equation-constrained optimization. At each major augmented Lagrangian iteration, the expensive optimization subproblem involving the full nonlinear system is replaced by an empirical quadrature-based hyperreduced model constructed on-the-fly. To ensure convergence of these inexact augmented Lagrangian subproblems, we develop a bound-constrained trust-region method that allows for inexact gradient evaluations, and specialize it to our specific setting that leverages hyperreduced models. This approach circumvents a traditional training phase because the models are built on-the-fly in accordance with the requirements of the trust-region convergence theory. Two numerical experiments (constrained aerodynamic shape design) demonstrate the convergence and efficiency of the proposed work. A speedup of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>12</mn>\u0000 <mo>.</mo>\u0000 <mn>7</mn>\u0000 <mo>×</mo>\u0000 </mrow>\u0000 <annotation>$$ 12.7times $$</annotation>\u0000 </semantics></math> (for all computational costs, even costs traditionally considered “offline” such as snapshot collection and data compression) relative to a standard optimization approach that does not leverage model reduction is shown.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 4","pages":"621-645"},"PeriodicalIF":1.7,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A High-Order Finite Element Method for Solving Two-Dimensional Fractional Rayleigh–Stokes Problem for a Heated Generalized Second Grade Fluid","authors":"Eric Ngondiep","doi":"10.1002/fld.5361","DOIUrl":"https://doi.org/10.1002/fld.5361","url":null,"abstract":"<div>\u0000 \u0000 <p>This article develops a high-order finite element scheme in an approximate solution of the two-dimensional Rayleigh–Stokes problem for a heated generalized second-grade fluid with fractional derivatives. The constructed approach consists of approximating the exact solution by interpolation in time while the finite element technique is used in the approximation of the spatial derivatives. This combination is simple and easy to implement. The stability and error estimates of the developed strategy are deeply analyzed in the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>∞</mi>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {L}^{infty } $$</annotation>\u0000 </semantics></math>-norm. The theoretical studies suggest that the proposed method is unconditionally stable, convergent with order <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>O</mi>\u0000 <mo>(</mo>\u0000 <msup>\u0000 <mrow>\u0000 <mi>σ</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>1</mn>\u0000 <mo>+</mo>\u0000 <mi>γ</mi>\u0000 </mrow>\u0000 </msup>\u0000 <mo>+</mo>\u0000 <msup>\u0000 <mrow>\u0000 <mi>h</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>p</mi>\u0000 </mrow>\u0000 </msup>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$$ Oleft({sigma}^{1+gamma }+{h}^pright) $$</annotation>\u0000 </semantics></math>, faster, and more efficient than a broad range of numerical schemes discussed in the literature for the considered time fractional partial differential equation. Some numerical examples are carried out to show the applicability and viability of the new algorithm.</p>\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 4","pages":"605-620"},"PeriodicalIF":1.7,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monolithic Newton-Multigrid Finite Element Methods for the Simulation of Thixoviscoplastic Flows","authors":"Naheed Begum,&nbsp;Abderrahim Ouazzi,&nbsp;Stefan Turek","doi":"10.1002/fld.5360","DOIUrl":"https://doi.org/10.1002/fld.5360","url":null,"abstract":"<p>In this paper, we shall be concerned with the development, application, and numerical analysis of the monolithic Newton-Multigrid finite element method (FEM) to simulate thixoviscoplastic (TVP) flows. We demonstrate the importance of robustness and efficiency of Newton-Multigrid FEM solver for obtaining accurate solutions. To put our work in proper perspective w.r.t. the delicate challenge of obtaining accurate numerical solutions for TVP flow problems, we content our investigation to TVP quasi-Newtonian modeling approach with an extensive analysis on lid-driven cavity flows, and expose the impact of thixotropic scale in 4:1 contraction configuration application. fldauth.cls class file for setting papers for the <i>International Journal for Numerical Methods in Fluids</i>. Copyright 2010 John Wiley &amp; Sons Ltd.</p><p>In this paper, we shall be concerned with the development, application, and numerical analysis of the monolithic Newton-Multigrid finite element method (FEM) to simulate thixoviscoplastic (TVP) flows. We demonstrate the importance of robustness and efficiency of Newton-Multigrid FEM solver for obtaining accurate solutions. To put our work in proper perspective w.r.t. the delicate challenge of obtaining accurate numerical solutions for TVP flow problems, we restrict our investigation to TVP quasi-Newtonian modeling approach and lid-driven cavity flows.</p>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 4","pages":"565-604"},"PeriodicalIF":1.7,"publicationDate":"2024-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5360","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}