Computers & Mathematics with Applications最新文献

Flow through a prosthetic mechanical aortic valve: Numerical model and experimental study 流经人工机械主动脉瓣：数值模型和实验研究

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-27 DOI: 10.1016/j.camwa.2024.09.010

引用次数: 0

A hybrid lattice Boltzmann and finite difference method for two-phase flows with soluble surfactants 可溶性表面活性剂两相流的晶格玻尔兹曼和有限差分混合方法

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-27 DOI: 10.1016/j.camwa.2024.09.022

{"title":"A hybrid lattice Boltzmann and finite difference method for two-phase flows with soluble surfactants","authors":"","doi":"10.1016/j.camwa.2024.09.022","DOIUrl":"10.1016/j.camwa.2024.09.022","url":null,"abstract":"<div><div>A hybrid method is developed to simulate two-phase flows with soluble surfactants. In this method, the interface and bulk surfactant concentration equations of diffuse-interface form, which include source terms to consider surfactant adsorption and desorption dynamics, are solved in the entire fluid domain by the finite difference method, while two-phase flows are solved by a lattice Boltzmann color-gradient model, which can accurately simulate binary fluids with unequal densities. The flow and interface surfactant concentration fields are coupled by a modified Langmuir equation of state, which allows for surfactant concentration beyond critical micelle concentration. The capability and accuracy of the hybrid method are first validated by simulating three numerical examples, including the adsorption of bulk surfactants onto the interface of a stationary droplet, the droplet migration in a constant surfactant gradient, and the deformation of a surfactant-laden droplet in a simple shear flow, in which the numerical results are compared with theoretical solutions and available literature data. Then, the hybrid method is applied to simulate the buoyancy-driven bubble rise in a surfactant solution, in which the influence of surfactants is identified for varying wall confinement, density ratio, Eotvos number and Biot number. It is found that surfactants exhibit a retardation effect on the bubble rise due to the Marangoni stress that resists interface motion, and the retardation effect weakens as the Eotvos or Biot number increases. We further show that the weakened retardation effect at higher Biot numbers is attributed to a decreased non-uniform effect of surfactants at the interface. By comparing with the Cahn-Hilliard phase-field method, we also show that the present method conserves the mass for each fluid, improves numerical stability especially at high density ratio and Eotvos number, and does not need the selection of free parameters, thus breaking the limitations of the existing method.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimized five-by-five block preconditioning for efficient GMRES convergence in curvature-based image deblurring 优化五乘五块预处理，在基于曲率的图像去模糊中实现高效的 GMRES 收敛

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-27 DOI: 10.1016/j.camwa.2024.09.026

引用次数: 0

The asymptotic preserving unified gas kinetic scheme for the multi-scale kinetic SIR epidemic model 多尺度动力学 SIR 流行病模型的渐近保留统一气体动力学方案

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-26 DOI: 10.1016/j.camwa.2024.09.021

{"title":"The asymptotic preserving unified gas kinetic scheme for the multi-scale kinetic SIR epidemic model","authors":"","doi":"10.1016/j.camwa.2024.09.021","DOIUrl":"10.1016/j.camwa.2024.09.021","url":null,"abstract":"<div><div>In this paper, we present an asymptotic preserving scheme for the two-dimensional space-dependent and multi-scale kinetic SIR epidemic model which is widely used to model the spread of infectious diseases in populations. The scheme combines a discrete ordinate method for the velocity variables and finite volume method for the spatial and time variables. The idea of unified gas kinetic scheme (UGKS) is used to construct the numerical boundary fluxes which needs the formal integral solutions of the model. Due to the coupling of the three transfer equations in the SIR model, it is difficult to obtain these integral solutions dependently. We decouple the system by constructing the fluxes in a separate way. Then following the framework of UGKS we can obtain the macro auxiliary quantities which is needed in the scheme. Thus the SIR model can be solved in the sequential way. In addition, we can show numerically that the scheme is second-order accurate both in space and time. Moreover, it can not only capture the solution of the diffusion limit equations without requiring the cell size and time step being related to the smallness of the scaling parameters, but also resolve the solution in hyperbolic regime in a natural way. Furthermore, the positive property of the UGKS is analyzed in detail, and through adding time step constraint conditions and applying nodal limiters together, the positive UGKS, called <span><math><mi>P</mi><mi>P</mi><mi>U</mi><mi>G</mi><mi>K</mi><msup><mrow><mi>S</mi></mrow><mrow><mn>2</mn><mo>−</mo><mi>o</mi><mi>r</mi><mi>d</mi><mi>e</mi><mi>r</mi></mrow></msup></math></span>, is obtained. Moreover, in order release the time step constraints in the diffusion regime, a temporal first-order accuracy positive preserving UGKS, called <span><math><mi>P</mi><mi>P</mi><mi>U</mi><mi>G</mi><mi>K</mi><msup><mrow><mi>S</mi></mrow><mrow><mn>1</mn><mo>−</mo><mi>o</mi><mi>r</mi><mi>d</mi><mi>e</mi><mi>r</mi></mrow></msup></math></span>, is proposed. Finally, several numerical tests are included to validate the performance of the proposed schemes.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Robust boundary integral equations for the solution of elastic scattering problems via Helmholtz decompositions 通过亥姆霍兹分解求解弹性散射问题的稳健边界积分方程

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-26 DOI: 10.1016/j.camwa.2024.09.013

{"title":"Robust boundary integral equations for the solution of elastic scattering problems via Helmholtz decompositions","authors":"","doi":"10.1016/j.camwa.2024.09.013","DOIUrl":"10.1016/j.camwa.2024.09.013","url":null,"abstract":"<div><div>Helmholtz decompositions of the elastic fields open up new avenues for the solution of linear elastic scattering problems via boundary integral equations (BIE) (Dong et al. (2021) <span><span>[20]</span></span>). The main appeal of this approach is that the ensuing systems of BIE feature only integral operators associated with the Helmholtz equation. However, these BIE involve non standard boundary integral operators that do not result after the application of either the Dirichlet or the Neumann trace to Helmholtz single and double layer potentials. Rather, the Helmholtz decomposition approach leads to BIE formulations of elastic scattering problems with Neumann boundary conditions that involve boundary traces of the Hessians of Helmholtz layer potential. As a consequence, the classical combined field approach applied in the framework of the Helmholtz decompositions leads to BIE formulations which, although robust, are not of the second kind. Following the regularizing methodology introduced in Boubendir et al. (2015) <span><span>[6]</span></span> we design and analyze novel robust Helmholtz decomposition BIE for the solution of elastic scattering that are of the second kind in the case of smooth scatterers in two dimensions. We present a variety of numerical results based on Nyström discretizations that illustrate the good performance of the second kind regularized formulations in connections to iterative solvers.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A mixed virtual element method for the two-dimensional Navier-Stokes equations in stream-function formulation 流函数形式的二维纳维-斯托克斯方程混合虚拟元素法

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-24 DOI: 10.1016/j.camwa.2024.09.020

{"title":"A mixed virtual element method for the two-dimensional Navier-Stokes equations in stream-function formulation","authors":"","doi":"10.1016/j.camwa.2024.09.020","DOIUrl":"10.1016/j.camwa.2024.09.020","url":null,"abstract":"<div><div>This work presents the formulation and analysis of a <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>−</mo></math></span> conforming mixed virtual element method (VEM) for the two-dimensional stationary incompressible Navier-Stokes (NS) equations in stream-function formulation. By representing the velocity field as the curl of a stream function, we recast the second-order NS system into a fourth-order nonlinear equation for the scalar stream function, inherently satisfying the incompressibility constraint. Introducing a vorticity variable enables construction of <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>−</mo></math></span> conforming VEM spaces for both stream function and vorticity and circumventing stringent <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>−</mo></math></span> continuity constraints. The proposed method provides an initial exploration of stream function-vorticity discretizations on general polygonal meshes using the flexible VEM of arbitrary order. Existence and uniqueness of discrete solutions are established theoretically under a small data assumption. Optimal error estimates are then derived in the energy norm for the stream function, <span><math><msup><mrow><mi>H</mi></mrow><mrow><mn>1</mn></mrow></msup><mo>−</mo></math></span> norm for the stream function and <span><math><msup><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>−</mo></math></span> norm for the vorticity, rigorously demonstrating convergence. Numerical results validate the error analysis and illustrate the accuracy and robustness of the mixed VEM for simulation of incompressible flows on complex geometries.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A hybrid model for accurate prediction of composite longitudinal elastic modulus 精确预测复合材料纵向弹性模量的混合模型

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-24 DOI: 10.1016/j.camwa.2024.09.019

{"title":"A hybrid model for accurate prediction of composite longitudinal elastic modulus","authors":"","doi":"10.1016/j.camwa.2024.09.019","DOIUrl":"10.1016/j.camwa.2024.09.019","url":null,"abstract":"<div><div>This research presents a novel hybrid model that integrates a physical-based empirical model with an Artificial Neural Network (ANN) to accurately predict the longitudinal modulus of elasticity for composites under compression. The study focuses on a composite material with a pore inclusion within an ABS plastic matrix, exploring various pore volumes, orientations, and shapes. As part of the proposed hybrid model, a regression-type neural network was trained in MATLAB® to predict and correct discrepancies between the Generalized Stiffness Formulation (GSF) homogenization-based modeling method and the collected compression experimental test results. Using MATLAB® neural network, random error datasets were used to train the feed-forward neural network, and the remaining error datasets were used for validating the performance of the proposed hybrid modeling scheme.</div><div>The hybrid model demonstrated superior performance, achieving the lowest Mean Error (ME) of 0.1684864, Mean Absolute Error (MAE) of 1.051846, Mean Squared Error (MSE) of 3.500952, and highest R-squared of 0.998797. The proposed hybrid model outperformed both the Generalized Stiffness Formulation (GSF) and standalone ANN models. The significant improvement in prediction accuracy underscores the novelty and robustness of the hybrid approach in composite material modeling. Furthermore, this method can be used to refine any existing physical model by focusing on improving these established models to match experimental results and reducing the discrepancies, which offers a more efficient and attractive strategy for accurate predictions.</div></div>","PeriodicalId":55218,"journal":{"name":"Computers & Mathematics with Applications","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mathematical modeling and numerical multigoal-oriented a posteriori error control and adaptivity for a stationary, nonlinear, coupled flow temperature model with temperature dependent density 静态、非线性、密度随温度变化的耦合流动温度模型的数学建模和面向多目标的后验误差控制与适应性数值计算

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-24 DOI: 10.1016/j.camwa.2024.09.017

引用次数: 0

A mixed immersed finite element method for fourth-order interface problems on surfaces 表面四阶界面问题的混合沉浸式有限元法

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-24 DOI: 10.1016/j.camwa.2024.09.012

引用次数: 0

A stabilizer-free weak Galerkin mixed finite element method for the biharmonic equation 双谐波方程的无稳定子弱 Galerkin 混合有限元法

IF 2.9 2区数学

Computers & Mathematics with Applications Pub Date : 2024-09-24 DOI: 10.1016/j.camwa.2024.09.011

引用次数: 0