International Journal for Numerical Methods in Fluids最新文献_第8页

A fully decoupled linearized and second-order accurate numerical scheme for two-phase magnetohydrodynamic flows 两相磁流体动力学流的完全解耦线性化二阶精确数值方案

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-12-17 DOI: 10.1002/fld.5253

Danxia Wang, Yuan Guo, Fang Liu, Hongen Jia, Chenhui Zhang

引用次数: 0

Computational fluid–structure interaction framework for passive feathering and cambering in flapping insect wings 昆虫扑翼被动羽化和弯曲的流固耦合计算框架

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-29 DOI: 10.1002/fld.5251

Daisuke Ishihara, Minato Onishi

{"title":"Computational fluid–structure interaction framework for passive feathering and cambering in flapping insect wings","authors":"Daisuke Ishihara, Minato Onishi","doi":"10.1002/fld.5251","DOIUrl":"10.1002/fld.5251","url":null,"abstract":"In flapping insect wings, veins support flexible wing membranes such that the wings form feathering and cambering motions passively from large elastic deformations. These motions are essentially important in unsteady aerodynamics of insect flapping flight. Hence, the underlying mechanism of this phenomenon is an important issue in studies on insect flight. Systematic parametric studies on strong coupling between a model wing describing these elastic deformations and the surrounding fluid, which is a direct formulation of this phenomenon, will be effective for solving this issue. The purpose of this study is to develop a robust numerical framework for these systematic parametric studies. The proposed framework consists of two novel numerical methods: (1) A fully parallelized solution method using both algebraic splitting and semi-implicit scheme for monolithic fluid–structure interaction (FSI) equation systems, which is numerically stable for a wide range of properties such as solid-to-fluid mass ratios and large body motions, and large elastic deformations. (2) A structural mechanics model for insect flapping wings using pixel modeling (pixel model wing), which is combined with explicit node-positioning to reduce computational costs significantly in controlling fluid meshes. The validity of the proposed framework is demonstrated for some benchmark problems and a dynamically scaled model incorporating actual insect data. Finally, from a parametric study for the pixel model wing flapped in fluid with a wide range of solid-to-fluid mass ratios, we find a FSI mechanism of feathering and cambering motions in flapping insect wings.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 4","pages":"435-481"},"PeriodicalIF":1.8,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5251","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138494663","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

Layered shallow water equations: Spatiotemporally varying layer ratios with specific adaptation to wet/dry interfaces 层状浅水方程:时空变化的层比与特定的适应湿/干界面

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-23 DOI: 10.1002/fld.5249

Naveed Ul Hassan Bhat, Gourabananda Pahar

{"title":"Layered shallow water equations: Spatiotemporally varying layer ratios with specific adaptation to wet/dry interfaces","authors":"Naveed Ul Hassan Bhat, Gourabananda Pahar","doi":"10.1002/fld.5249","DOIUrl":"10.1002/fld.5249","url":null,"abstract":"The study of multilayered shallow water equations has developed from a consideration of immiscible layers as a vertical mesh to the layer bounds as imaginary extremes for vertical integration of the flow equations. In the current work, a quasi three-dimensional flow model has been developed with the consideration of the spatiotemporal flexibility/variability of the pervious vertical discretization/layer ratios. Thus, in principle, vertical layering offers a nonuniform grid with a temporal variation. The system of equations thus formulated comprises a conservative part and the appended source/sink terms. These source/sink terms pertain to the inter-layer interactions such as mass/momenta transfer and interfacial stress, which have been treated in a novel implicit form alongwith the subgrid-scale eddy-viscosity for interlayer shear. They are integrated into the system through different physical considerations so as to arrive at a well-balanced numerical scheme in a regular finite volume grid. The model has been validated through the standard test-cases highlighting the conservation properties and the model's adaptability to uniform and nonuniform vertical meshes alongwith the spatiotemporal transitions of layer ratios, with a specific interest in limiting cases of wet/dry fronts. The increase in layer ratios tends to nearly replicate the full-scale model results in experimental scenarios at a lesser computational overhead.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 4","pages":"397-434"},"PeriodicalIF":1.8,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138494662","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

Enhancing physics informed neural networks for solving Navier–Stokes equations 增强物理信息神经网络求解Navier-Stokes方程

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-20 DOI: 10.1002/fld.5250

Ayoub Farkane, Mounir Ghogho, Mustapha Oudani, Mohamed Boutayeb

{"title":"Enhancing physics informed neural networks for solving Navier–Stokes equations","authors":"Ayoub Farkane, Mounir Ghogho, Mustapha Oudani, Mohamed Boutayeb","doi":"10.1002/fld.5250","DOIUrl":"10.1002/fld.5250","url":null,"abstract":"<div>\u0000 \u0000 Fluid mechanics is a critical field in both engineering and science. Understanding the behavior of fluids requires solving the Navier–Stokes equation (NSE). However, the NSE is a complex partial differential equation that can be challenging to solve, and classical numerical methods can be computationally expensive. In this paper, we propose enhancing physics-informed neural networks (PINNs) by modifying the residual loss functions and incorporating new computational deep learning techniques. We present two enhanced models for solving the NSE. The first model involves developing the classical PINN for solving the NSE, based on a stream function approach to the velocity components. We have added the pressure training loss function to this model and integrated the new computational training techniques. Furthermore, we propose a second, more flexible model that directly approximates the solution of the NSE without making any assumptions. This model significantly reduces the training duration while maintaining high accuracy. Moreover, we have successfully applied this model to solve the three-dimensional NSE. The results demonstrate the effectiveness of our approaches, offering several advantages, including high trainability, flexibility, and efficiency.\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 4","pages":"381-396"},"PeriodicalIF":1.8,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138494660","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

Flow resistance co-efficient of meandering river in alluvial plain and its prediction using artificial neural network 冲积平原曲流河流阻力系数及其人工神经网络预测

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-20 DOI: 10.1002/fld.5247

Sayed Sadulla Ahmed, Susmita Ghosh, Abdul Karim Barbhuiya

{"title":"Flow resistance co-efficient of meandering river in alluvial plain and its prediction using artificial neural network","authors":"Sayed Sadulla Ahmed, Susmita Ghosh, Abdul Karim Barbhuiya","doi":"10.1002/fld.5247","DOIUrl":"10.1002/fld.5247","url":null,"abstract":"A proper estimation of flow resistance coefficient of river is essential for precise simulations of river hydraulics. In addition to the cross-sectional geometry and hydraulic parameters, the alignment of the channel affects the flow resistance coefficient in case of meandering rivers. In the present study, a rigorous field study of 131 km along the Barak River was conducted to assess the influence of meandering on the flow resistance coefficient. The values of flow resistance co-efficient were calculated using Chezy and Manning's equations with measured field data and the values from both are compared. However, the variation in the flow resistance co-efficient along the channel calculated from Manning's equation is significantly less as it does not consider the undulation and meandering. Using these field data, an artificial neural network (ANN) model has been developed to predict the cross-sectional averaged flow resistance for meandering river. The model considered the influence of relative curvature, depth of flow, bed particle size, Froude number and Reynolds number including water temperature for accurate predictions of flow resistance coefficient. The ANN model was tested and validated using 237 field data sample. The values of the statistical parameters indicate a very good fit to the training dataset with coefficient of determination (R2) = 0.9566 for training and good fit for testing with R2 = 0.8131. The developed ANN model has been compared with other model with the same data set to check its applicability.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 3","pages":"364-379"},"PeriodicalIF":1.8,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138494661","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

An immersed boundary method-discrete unified gas kinetic scheme simulation of particle-laden turbulent channel flow on a nonuniform orthogonal mesh 在非均匀正交网格上模拟含颗粒湍流通道流的沉浸边界法-离散统一气体动力学方案

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-13 DOI: 10.1002/fld.5246

Kairzhan Karzhaubayev, Lian-Ping Wang, Cheng Peng, Dauren Zhakebayev

引用次数: 0

A fast and accurate method for transport and dispersion of phosphogypsum in coastal zones: Application to Jorf Lasfar 沿海地区磷石膏迁移和扩散的快速准确方法：在 Jorf Lasfar 的应用

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-13 DOI: 10.1002/fld.5248

Abdelouahed Ouardghi, Mohammed Seaid, Mofdi El-Amrani, Nabil El Mocayd

{"title":"A fast and accurate method for transport and dispersion of phosphogypsum in coastal zones: Application to Jorf Lasfar","authors":"Abdelouahed Ouardghi, Mohammed Seaid, Mofdi El-Amrani, Nabil El Mocayd","doi":"10.1002/fld.5248","DOIUrl":"10.1002/fld.5248","url":null,"abstract":"<div>\u0000 \u0000 We present a numerical method for modelling and simulation of transport and dispersion of phosphogypsum in the Jorf Lasfar coastal zone located on the Atlantic Ocean at Morocco. The governing equations consist of the well-established barotropic ocean model including the barometric pressure, friction terms, Coriolis and wind stresses. To model transport and dispersion of phosphogypsum we consider an advection-diffusion equation with an anisotropic dispersion tensor and source terms. As a numerical solver, we propose a novel multilevel adaptive semi-Lagrangian finite element method. The proposed method combines the modified method of characteristics to deal with convection terms, the finite element discretization to handle complex geometries, a projection-based algorithm to solve the Stokes problem, and an adaptive <math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mrow>\u0000 <mi>L</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation>$$ {mathrm{L}}^2 $$</annotation>\u0000 </semantics></math>-projection using quadrature rules to improve the efficiency and accuracy of the method. Numerical results are presented to demonstrate the high resolution of the proposed method and to confirm its capability to provide accurate and efficient simulations for transport and dispersion of phosphogypsum in the Jorf Lasfar coastal zone.\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 3","pages":"336-363"},"PeriodicalIF":1.8,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136351429","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

An improved slip-wall model for large eddy simulation and its implementation in the local domain-free discretization method 用于大涡度模拟的改进滑移壁模型及其在局部无域离散法中的应用

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-10 DOI: 10.1002/fld.5244

D. Zhang, C. H. Zhou

{"title":"An improved slip-wall model for large eddy simulation and its implementation in the local domain-free discretization method","authors":"D. Zhang, C. H. Zhou","doi":"10.1002/fld.5244","DOIUrl":"10.1002/fld.5244","url":null,"abstract":"In this paper, a slip-wall model for large eddy simulation (LES) is improved and implemented in an immersed boundary method named the local domain-free discretization (DFD) method. Considering that the matching location may be in the viscous sublayer, the physics-based interpretation of a Robin-type wall closure is complemented. Then, the slip-wall wall model is improved, in which the slip length is redefined and the Robin boundary condition is imposed at the solid wall. The improved slip-wall model is implemented in the local DFD method to evaluated the tangential velocity at an exterior dependent node, and then the requirement on high resolution of boundary layers can be alleviated. The non-equilibrium effects are accounted for by adding an explicit correction to the wall shear stress. In order to validate the present wall-modeled LES/DFD method, a series of turbulent channel flows at various Reynolds numbers, the flow over periodic hills and the flows over a NACA 4412 airfoil at a high Reynolds number are simulated. The predicted results agree well with the referenced experimental data and numerical results. Especially, the results of the separated flow over the airfoil at a near-stall condition demonstrate the performance of the present wall-modeled LES/DFD method for complex flows.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 3","pages":"297-317"},"PeriodicalIF":1.8,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135142054","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

Uncertainty quantification and identification of SST turbulence model parameters based on Bayesian optimization algorithm in supersonic flow 基于贝叶斯优化算法的超音速流中 SST 湍流模型参数的不确定性量化与识别

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-02 DOI: 10.1002/fld.5245

Maotao Yang, Mingming Guo, Yi Zhang, Ye Tian, Miaorong Yi, Jialing Le, Hua Zhang

{"title":"Uncertainty quantification and identification of SST turbulence model parameters based on Bayesian optimization algorithm in supersonic flow","authors":"Maotao Yang, Mingming Guo, Yi Zhang, Ye Tian, Miaorong Yi, Jialing Le, Hua Zhang","doi":"10.1002/fld.5245","DOIUrl":"10.1002/fld.5245","url":null,"abstract":"The Reynolds-Averaged Navier–Stokes (RANS) model is the main model in engineering applications today. However, the normal value of the closure coefficient of the RANS turbulence model is determined based on some simple basic flows and may no longer be applicable for complex flows. In this paper, the closure coefficient of shear stress transport (SST) turbulence model is recalibrated by combining Bayesian method and particle swarm optimization algorithm, so as to improve the numerical simulation accuracy of wall pressure in supersonic flow. First, the obtained prior samples were numerically calculated, and the Sobol index of the closure coefficient was calculated by sensitivity analysis method to characterize the sensitivity of the wall pressure to the model parameters. Second, combined with the uncertainty of propagation parameters by non-intrusive polynomial chaos (NIPC). Finally, Bayesian optimization is used to quantify the uncertainty and obtain the maximum likelihood function estimation and optimal parameters. The results show that the maximum relative error of wall pressure predicted by the SST turbulence model decreases from 29.71% to 9.00%, and the average relative error decreases from 9.86% to 3.67% through the parameter calibration of Bayesian optimization method. In addition, the system evaluated the calibration effect of three criteria, and the calibration results parameters under the three criteria were all better than the calculated results of the nominal values. Meanwhile, the velocity profile and density profile of the flow field were also analyzed. Finally, the same calibration method was applied to the supersonic hollow cylinder and BSL (Baseline) turbulence model, and the same calibration results were obtained, which verified the universality of the calibration method.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 3","pages":"277-296"},"PeriodicalIF":1.8,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135875584","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

A linear low effort stabilization method for the Euler equations using discontinuous Galerkin methods 使用非连续伽勒金方法的欧拉方程线性低强度稳定方法

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2023-11-01 DOI: 10.1002/fld.5243

Michel Bänsch, Jörn Behrens, Stefan Vater

{"title":"A linear low effort stabilization method for the Euler equations using discontinuous Galerkin methods","authors":"Michel Bänsch, Jörn Behrens, Stefan Vater","doi":"10.1002/fld.5243","DOIUrl":"10.1002/fld.5243","url":null,"abstract":"We present a novel and simple yet intuitive approach to the stabilization problem for the numerically solved Euler equations with gravity source term relying on a low-order nodal Discontinuous Galerkin Method (DGM). Instead of assuming isothermal or polytropic solutions, we only take a hydrostatic balance as a given property of the flow and use the hydrostatic equation to calculate a hydrostatic pressure reconstruction that replaces the gravity source term. We compare two environments that both solve the Euler equations using the DGM: deal.II and StormFlash. We utilize StormFlash as it allows for the use of the novel stabilization method. Without stabilization, StormFlash does not yield results that resemble correct physical behavior while the results with stabilization for StormFlash, as well as deal.II model the fluid flow more accurately. Convergence rates for deal.II do not match the expected order while the convergence rates for StormFlash with the stabilization scheme (with the exceptions for the L<math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mrow></mrow>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {}_2 $$</annotation>\u0000 </semantics></math> errors for momentum) meet the expectation. The results from StormFlash with stabilization also fit reference solutions from the literature much better than those from deal.II. We conclude that this novel scheme is a low cost approach to stabilize the Euler equations while not limiting the flow in any way other than it being in hydrostatic balance.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 3","pages":"256-276"},"PeriodicalIF":1.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135271699","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