International Journal for Numerical Methods in Fluids最新文献_第2页

Multi-Objective Optimization and Experimental Research of Ship Form Based on Improved Bare-Bones Multi-Objective Particle Swarm Optimization Algorithm

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-21 DOI: 10.1002/fld.5346

Jie Liu, Baoji Zhang, Yuyang Lai, Liqiao Fang

{"title":"Multi-Objective Optimization and Experimental Research of Ship Form Based on Improved Bare-Bones Multi-Objective Particle Swarm Optimization Algorithm","authors":"Jie Liu, Baoji Zhang, Yuyang Lai, Liqiao Fang","doi":"10.1002/fld.5346","DOIUrl":"https://doi.org/10.1002/fld.5346","url":null,"abstract":"<div>\u0000 \u0000 Ship form optimization poses a complex and high-dimensional engineering challenge. Therefore, when conducting multi-objective optimization research of ship forms, traditional intelligent optimization algorithms are prone to falling into local optima solution and difficult to converge. In order to effectively improve the diversity and convergence performance of the algorithm, this paper improves the bare-bones multi-objective particle swarm optimization (BBMOPSO) algorithm by dynamically adjusting the local and global search step sizes, and verifies the algorithm's reliability through standard function testing. Then, a multi-objective optimization design framework with high efficiency and high integration is constructed. Taking DTMB 5512 as the research case, Free Form Deformation (FFD) method is used for hull deformation, and the proposed algorithm is used for multi-objective optimization of resistance performance and motion response. Ship model tests were conducted on the DTMB 5512's original hull. And the numerical simulations were compared with the ship model tests. Finally, under the constructed multi-objective optimization design framework, satisfactory solutions were obtained through the improved algorithm, which confirms the effectiveness and practicality of the improved algorithm. The results show that the algorithm improved in this paper can provide some theoretical basis and technical support for green ship design and low-carbon shipping.\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 3","pages":"267-282"},"PeriodicalIF":1.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117678","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}

引用次数: 0

Computation of Deformable Interface Two-Phase Flows: A Semi-Lagrangian Finite Element Approach

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-14 DOI: 10.1002/fld.5342

Daniel B. V. Santos, Rafael Vidal, Prashant Valluri, Gustavo R. Anjos

{"title":"Computation of Deformable Interface Two-Phase Flows: A Semi-Lagrangian Finite Element Approach","authors":"Daniel B. V. Santos, Rafael Vidal, Prashant Valluri, Gustavo R. Anjos","doi":"10.1002/fld.5342","DOIUrl":"https://doi.org/10.1002/fld.5342","url":null,"abstract":"<div>\u0000 \u0000 This work aims at presenting a new computational approach to study two and three dimensional two-phase flows and two dimensional coalescence phenomenon using direct numerical simulation. The flows are modeled by the incompressible Navier–Stokes equations, which are approximated by the finite element method. The Galerkin formulation is used to discretize the Navier–Stokes equations in the spatial domain and the semi-Lagrangian method is used to discretize the material derivative. In order to satisfy the Ladyzhenskaya–Babuška–Brezzi condition, high-order stable pair of elements are used, with pressure and velocity fields being calculated on different degrees of freedom in the unstructured mesh nodes. The interface is modeled by an unfitted adaptive moving mesh, where interface nodes are tracked in a Lagrangian fashion and moved with the velocity solution of the fluid motion equations. The surface tension is computed using the interface curvature and the gradient of a Heaviside function, and added in the momentum equations as a body force. In order to avoid undesired spurious modes at the interface due to high property ratios, a smooth transition between fluid properties is defined on the interface region. Several benchmark tests have been carried out to validate the proposed approach, and the obtained results have demonstrated agreement with analytical solutions and numerical results reported in the literature. A coalescence model is also proposed based on geometric criteria and results show interesting dynamics.\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 3","pages":"233-243"},"PeriodicalIF":1.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143115014","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}

引用次数: 0

Collocation Finite Element Method for the Fractional Fokker–Planck Equation

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-13 DOI: 10.1002/fld.5343

Hatice Karabenli, Alaattin Esen, Yusuf Uçar

{"title":"Collocation Finite Element Method for the Fractional Fokker–Planck Equation","authors":"Hatice Karabenli, Alaattin Esen, Yusuf Uçar","doi":"10.1002/fld.5343","DOIUrl":"https://doi.org/10.1002/fld.5343","url":null,"abstract":"In this study, the approximate results of the fractional Fokker–Planck equations have been investigated. First, finite element schemes have been obtained using collocation finite element method based on the trigonometric quintic B-spline basis functions. Then, the present method is tested on two fundamental problems having appropriate initial conditions. The newly obtained numerical results contained the error norms <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>L</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {L}_2 $$</annotation>\u0000 </semantics></math> and <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>L</mi>\u0000 <mi>∞</mi>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {L}_{infty } $$</annotation>\u0000 </semantics></math> for various temporal and spatial steps are compared with the exact ones and other solutions. More accurate results have been obtained for large numbers of spatial and temporal elements.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 3","pages":"224-232"},"PeriodicalIF":1.7,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5343","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114762","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}

引用次数: 0

Robust 3D multi-material hydrodynamics using discontinuous Galerkin methods

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-08 DOI: 10.1002/fld.5340

Weizhao Li, Aditya Pandare, Hong Luo, Jozsef Bakosi, Jacob Waltz

{"title":"Robust 3D multi-material hydrodynamics using discontinuous Galerkin methods","authors":"Weizhao Li, Aditya Pandare, Hong Luo, Jozsef Bakosi, Jacob Waltz","doi":"10.1002/fld.5340","DOIUrl":"https://doi.org/10.1002/fld.5340","url":null,"abstract":"A high-order discontinuous Galerkin (DG) method is presented for nonequilibrium multi-material (<math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>m</mi>\u0000 <mo>≥</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$$ mge 2 $$</annotation>\u0000 </semantics></math>) flow with sharp interfaces. Material interfaces are reconstructed using the algebraic THINC approach, resulting in a sharp interface resolution. The system assumes stiff velocity relaxation and pressure nonequilibrium. The presented DG method uses Dubiner's orthogonal basis functions on tetrahedral elements. This results in a unique combination of sharp multimaterial interfaces and high-order accurate solutions in smooth single-material regions. A novel shock indicator based on the interface conservation condition is introduced to mark regions with discontinuities. Slope limiting techniques are applied only in these regions so that nonphysical oscillations are eliminated while maintaining high-order accuracy in smooth regions. A local projection is applied on the limited solution to ensure discrete closure law preservation. The effectiveness of this novel limiting strategy is demonstrated for complex three-dimensional multi-material problems, where robustness of the method is critical. The presented numerical problems demonstrate that more accurate and efficient multi-material solutions can be obtained by the DG method, as compared to second-order finite volume methods.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 2","pages":"188-209"},"PeriodicalIF":1.7,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5340","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113182","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}

引用次数: 0

Novel lattice Boltzmann method for simulation of strongly shear thinning viscoelastic fluids

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-08 DOI: 10.1002/fld.5335

Richard Kellnberger, Tomasz Jüngst, Stephan Gekle

引用次数: 0

A finite volume scheme employing the multipoint flux approximation with diamond stencil for the diffusive-viscous wave equation on general polyhedral meshes

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-07 DOI: 10.1002/fld.5336

Di Yang, Zhiming Gao, Wenjing Yan

引用次数: 0

Optimizing Winglet Cant Angle for Enhanced Aircraft Wing Performance Using CFD Simulation and Hybrid ANN-GA

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-10-07 DOI: 10.1002/fld.5341

Vidhit Mandia, Vipul Sharma, Yash Chandra, Gaurav Kumar, Raj Kumar Singh

引用次数: 0

A volume-of-solid implicit volume penalty method for moving-body flows

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-09-19 DOI: 10.1002/fld.5334

Iason Tsetoglou, Mélody Cailler, Pierre Bénard, Ghislain Lartigue, Vincent Moureau, Julien Réveillon

{"title":"A volume-of-solid implicit volume penalty method for moving-body flows","authors":"Iason Tsetoglou, Mélody Cailler, Pierre Bénard, Ghislain Lartigue, Vincent Moureau, Julien Réveillon","doi":"10.1002/fld.5334","DOIUrl":"https://doi.org/10.1002/fld.5334","url":null,"abstract":"An original Immersed Boundary Method for solving moving body flows is proposed. This method couples (i) a Lagrangian Volume-of-Solid description of the solid object avoiding conservation issues and (ii) a robust implicit volume penalty forcing embedded in a low-Mach number projection method to account for the solid's impact on the fluid dynamics. A new composite velocity field is introduced to describe both solid and fluid domains in a single set of governing equations. The accuracy of the method has been assessed on several academic cases, involving stationary or moving bodies and with different mesh resolutions. The predicted forces on the solid are in excellent agreement with body-fitted reference cases. The system of equations is also proven to be fully mass conservative. Application of the method on a two-dimensional vertical axis turbine case shows a <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>30</mn>\u0000 <mo>%</mo>\u0000 </mrow>\u0000 <annotation>$$ 30% $$</annotation>\u0000 </semantics></math> reduction in computational cost compared to a body-fitted method.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 2","pages":"117-150"},"PeriodicalIF":1.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5334","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117229","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}

引用次数: 0

Semi-implicit Lagrangian Voronoi approximation for the incompressible Navier–Stokes equations 不可压缩纳维-斯托克斯方程的半隐式拉格朗日 Voronoi 近似法

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-09-17 DOI: 10.1002/fld.5339

Ondřej Kincl, Ilya Peshkov, Walter Boscheri

{"title":"Semi-implicit Lagrangian Voronoi approximation for the incompressible Navier–Stokes equations","authors":"Ondřej Kincl, Ilya Peshkov, Walter Boscheri","doi":"10.1002/fld.5339","DOIUrl":"10.1002/fld.5339","url":null,"abstract":"We introduce semi-implicit Lagrangian Voronoi approximation (SILVA), a novel numerical method for the solution of the incompressible Euler and Navier–Stokes equations, which combines the efficiency of semi-implicit time marching schemes with the robustness of time-dependent Voronoi tessellations. In SILVA, the numerical solution is stored at particles, which move with the fluid velocity and also play the role of the generators of the computational mesh. The Voronoi mesh is rapidly regenerated at each time step, allowing large deformations with topology changes. As opposed to the reconnection-based Arbitrary-Lagrangian-Eulerian schemes, we need no remapping stage. A semi-implicit scheme is devised in the context of moving Voronoi meshes to project the velocity field onto a divergence-free manifold. We validate SILVA by illustrative benchmarks, including viscous, inviscid, and multi-phase flows. Compared to its closest competitor, the Incompressible Smoothed Particle Hydrodynamics method, SILVA offers a sparser stiffness matrix and facilitates the implementation of no-slip and free-slip boundary conditions.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 1","pages":"88-115"},"PeriodicalIF":1.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5339","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252123","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}

引用次数: 0

A new non-equilibrium modification of the k − ω $$ k-omega $$ turbulence model for supersonic turbulent flows with transverse jet 针对具有横向喷流的超音速湍流的 k-ω$$ k-omega $$ 湍流模型的新非平衡修正

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-09-17 DOI: 10.1002/fld.5337

Altynshash Naimanova, Assel Beketaeva

{"title":"A new non-equilibrium modification of the \u0000 \u0000 \u0000 k\u0000 −\u0000 ω\u0000 \u0000 $$ k-omega $$\u0000 turbulence model for supersonic turbulent flows with transverse jet","authors":"Altynshash Naimanova, Assel Beketaeva","doi":"10.1002/fld.5337","DOIUrl":"10.1002/fld.5337","url":null,"abstract":"The goal of this research is to propose a new modification of a non-equilibrium effect in the <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>k</mi>\u0000 <mo>−</mo>\u0000 <mi>ω</mi>\u0000 </mrow>\u0000 <annotation>$$ k-omega $$</annotation>\u0000 </semantics></math> turbulence model to better predict high-speed turbulent flows. For that, the two local compressibility coefficients are included in the balance production/dissipation terms in a specific dissipation rate equation. The specific dissipation rate reacts to changes in the local Mach number and density through these local coefficients. The developed model is applied to the numerical simulation of the spatial supersonic turbulent airflow with round hydrogen injection. In that, the effects of the proposed turbulence model on the flow field behavior (shock wave and vortex formations, shock wave/boundary layer interaction, and mixture layer) are studied via the solution of three-dimensional Favre-averaged Navier–Stokes equations with a third-order Essentially Non-Oscillatory scheme. A series of numerical experiments are performed, in which an allowable range of local constants by comparing results with experimental data is obtained. The non-equilibrium modification by simultaneous decrease of the turbulence kinetic energy and increase of the specific dissipation rate gives a good agreement of the hydrogen depth penetration with experimental data. Also, the numerical experiment of the supersonic airflow with a nitrogen jet shows wall pressure distribution is consistent well with experimental data.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"97 1","pages":"69-87"},"PeriodicalIF":1.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252122","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}

引用次数: 0