International Journal for Numerical Methods in Fluids最新文献_第9页

Hull form optimization research based on multi-precision back-propagation neural network approximation model 基于多精度反向传播神经网络近似模型的船体形式优化研究

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-05-01 DOI: 10.1002/fld.5291

Jie Liu, Baoji Zhang, Yuyang Lai, Liqiao Fang

{"title":"Hull form optimization research based on multi-precision back-propagation neural network approximation model","authors":"Jie Liu, Baoji Zhang, Yuyang Lai, Liqiao Fang","doi":"10.1002/fld.5291","DOIUrl":"10.1002/fld.5291","url":null,"abstract":"In order to shorten the optimization cycle of ship design optimization and solve the time-consuming problem of computational fluid dynamics (CFD) numerical calculation, this paper proposes a multi-precision back-propagation neural network (MP-BP) approximation technology. Fewer high-precision ship samples and more low-precision ship samples were used to construct an approximate model, back-propagation (BP) neural network was used to train multi-precision samples. So that the approximate model is as close as possible to the real model, and achieving the effect of high-precision approximation model. Subsequently, numerical verification and typical hull form verification are given. Based on CFD and Rankine theory, the multi-objective design optimization framework for ship comprehensive navigation performance is constructed. The multi-objective approximation model of KCS ship is constructed by MP-BP approximation technology, and optimized by particle swarm optimization (PSO) algorithm. The results show that the multi-objective optimization design framework using the MP-BP approximation model can capture the global optimal solution and improve the efficiency of the entire hull form design optimization. It can provide a certain degree of technical support for green ship and low-carbon shipping.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 8","pages":"1445-1460"},"PeriodicalIF":1.7,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140836116","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

Adaptive mesh based efficient approximations for Darcy scale precipitation–dissolution models in porous media 基于自适应网格的多孔介质中达西尺度降水-溶解模型的高效近似方法

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-04-28 DOI: 10.1002/fld.5294

Shridhar Kumar, Pratibhamoy Das, Kundan Kumar

{"title":"Adaptive mesh based efficient approximations for Darcy scale precipitation–dissolution models in porous media","authors":"Shridhar Kumar, Pratibhamoy Das, Kundan Kumar","doi":"10.1002/fld.5294","DOIUrl":"10.1002/fld.5294","url":null,"abstract":"In this work, we consider the Darcy scale precipitation–dissolution reactive transport 1D and 2D models in a porous medium and provide the adaptive mesh based numerical approximations for solving them efficiently. These models consist of a convection-diffusion-reaction PDE with reactions being described by an ODE having a nonlinear, discontinuous, possibly multi-valued right hand side describing precipitate concentration. The bulk concentration in the aqueous phase develops fronts and the precipitate concentration is described by a free and time-dependent moving boundary. The time adaptive moving mesh strategy, based on equidistribution principle in space and governed by a moving mesh PDE, is utilized and modified in the context of present problem for finite difference set up in 1D and finite element set up in 2D. Moreover, we use a predictor corrector based algorithm to solve the nonlinear precipitation–dissolution models. For equidistribution approach, we choose an adaptive monitor function and smooth it based on a diffusive mechanism. Numerical tests are performed to demonstrate the accuracy and efficiency of the proposed method by examples through finite difference approach for 1D and finite element approach in 2D. The moving mesh refinement accurately resolves the front location of Darcy scale precipitation–dissolution reactive transport model and reduces the computational cost in comparison to numerical simulations using a fixed mesh.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 8","pages":"1415-1444"},"PeriodicalIF":1.7,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140836393","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 extended discontinuous Galerkin shock tracking method 扩展的非连续伽勒金冲击跟踪方法

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-04-17 DOI: 10.1002/fld.5293

Jakob Vandergrift, Florian Kummer

引用次数: 0

A modified forcing approach in the Rothman–Keller method for simulations of flow phenomena at low capillary numbers 用于模拟低毛细管数流动现象的罗斯曼-凯勒方法中的修正强迫法

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-04-10 DOI: 10.1002/fld.5292

Anand Sudha, Martin Rohde

{"title":"A modified forcing approach in the Rothman–Keller method for simulations of flow phenomena at low capillary numbers","authors":"Anand Sudha, Martin Rohde","doi":"10.1002/fld.5292","DOIUrl":"10.1002/fld.5292","url":null,"abstract":"The lattice-Boltzmann method (LBM) is becoming increasingly popular for simulating multi-phase flows on the microscale because of its advantages in terms of computational efficiency. Many applications of the method are restricted to relatively simple geometries. When a more complex geometry is considered—circular and inclined microchannels—some important physical phenomena may not be accurately captured, especially at low capillary numbers. A Y-Y micro-fluidic channel, widely used for a range of applications, is an example of a more complex geometry. This work aims to capture the various flow phenomena, with an emphasis on parallel flow and leakage, using the Rothman–Keller (RK) model of the LBM. To this purpose, we modify the forcing term to implement the surface tension for use at low capillary numbers. We compare the simulation results of the RK model with and without the force modification with experiments, Volume of Fluid and the phase field method and observe that the modified forcing term is an improvement over the current RK model at low capillary numbers, and it also captures parallel flow and leakage more accurately than the other simulation techniques.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 8","pages":"1365-1383"},"PeriodicalIF":1.7,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/fld.5292","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140589010","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 reduced smoothed integration scheme of the cell-based smoothed finite element method for solving fluid–structure interaction on severely distorted meshes 基于单元的简化平滑有限元法的简化平滑积分方案，用于解决严重扭曲网格上的流固耦合问题

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-04-02 DOI: 10.1002/fld.5289

Tao He, Fang-Xing Lu, Xi Ma

引用次数: 0

Therapeutic Potential of Morin Hydrate Against Rifampicin Induced Hepato and Renotoxicity in Albino Wistar Rats: Modulation of Organ Function, Oxidative Stress and Inflammatory Response. 水合吗啉对利福平诱导的白化 Wistar 大鼠肝肾毒性的治疗潜力：调节器官功能、氧化应激和炎症反应

IF 1.7 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-04-01 Epub Date: 2023-08-04 DOI: 10.1007/s12291-023-01145-0

Harvesh Kumar Rana, Amit Kumar Singh, Abhay Kumar Pandey

{"title":"Therapeutic Potential of Morin Hydrate Against Rifampicin Induced Hepato and Renotoxicity in Albino Wistar Rats: Modulation of Organ Function, Oxidative Stress and Inflammatory Response.","authors":"Harvesh Kumar Rana, Amit Kumar Singh, Abhay Kumar Pandey","doi":"10.1007/s12291-023-01145-0","DOIUrl":"10.1007/s12291-023-01145-0","url":null,"abstract":"Tuberculosis (TB) is a challenging public health issue, particularly in poor and developing countries. Rifampicin (RIF) is one of the most common first-line anti-TB drugs but it is known for its adverse effects on the hepato-renal system. The present study investigated the efficacy of morin hydrate (MH) in protecting hepato-renal damage inflicted by RIF in rats. RIF (50 mg/kg), and a combination of RIF (50 mg/kg) and MH (50 mg/kg) were administered orally for 4 weeks in rats. Silymarin (50 mg/kg) was used as a positive control. Increased levels of serological parameters such as AST, ALT, ALP, LDH, GGT, bilirubin, triglyceride, total cholesterol, urea, uric acid, creatinine, TNF-α, IFN-γ, IL-6 along with the decreased level of IL-10, total protein and albumin were used as markers of hepatic and renal injury. Oxidative damage in the tissues was measured by the increase in lipid peroxidation and decline in GSH, SOD and catalase activities. Histopathology of liver slices was used to study hepatic architecture. Four-week RIF treatment produced altered serological parameters with an increase in pro-inflammatory cytokines in serum suggesting hepatotoxicity and nephrotoxicity. The antioxidant status of the liver and kidney (increased lipid peroxidation and decline in GSH, SOD and catalase) was compromised. Cellular damage and necrosis were observed in liver slices. MH supplementation with RIF improved hepato-renal functions by restoring the serum and tissue markers towards normal values. Histological observations authenticated the results. MH supplementation also reduced the production of pro-inflammatory cytokines. Thus, the results revealed that MH provides protection against RIF-induced hepato-renal injury.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"95 1","pages":"197-206"},"PeriodicalIF":1.7,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10987459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76652043","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

Comparative analysis of nondimensionalization approaches for solving the 2-D differentially heated cavity problem 解决二维不同加热腔问题的非尺寸化方法比较分析

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-03-30 DOI: 10.1002/fld.5285

F. I. Molina-Herrera, L. I. Quemada-Villagómez, J. L. Navarrete-Bolaños, H. Jiménez-Islas

引用次数: 0

A mathematical-boundary-recognition domain-decomposition Lattice Boltzmann method combined with large eddy simulation applied to airfoil aeroacoustics simulation 应用于机翼气动声学模拟的数学边界识别领域分解格点玻尔兹曼方法与大涡流模拟相结合

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-03-28 DOI: 10.1002/fld.5287

Qi Jia, Jin Zhang, Wen-zhi Liang, Pei-qing Liu, Qiu-lin Qu

{"title":"A mathematical-boundary-recognition domain-decomposition Lattice Boltzmann method combined with large eddy simulation applied to airfoil aeroacoustics simulation","authors":"Qi Jia, Jin Zhang, Wen-zhi Liang, Pei-qing Liu, Qiu-lin Qu","doi":"10.1002/fld.5287","DOIUrl":"10.1002/fld.5287","url":null,"abstract":"Being a direct computational aeroacoustics method, Lattice Boltzmann method (LBM) has great potential and broad application perspective in the field of numerical simulation of aerodynamic noise due to its low dispersion and low dissipation. A series of numerical algorithms and the related improvements based on the standard LBM method are proposed and developed in this paper to adapt to the airfoil noise calculation with complex grid at middle-high Reynolds number. First, a new mathematical-boundary-recognition algorithm based on Green's formula is proposed to deal with complex curved geometric models, which is validated by three-element airfoil 30P30N benchmark. Then, in order to reduce grid redundancy and improve computing efficiency, the grid refinement technique of domain decomposition model (DDM) is adopted and also improved, which is verified by calculating the flow and sound fields around 2D and 3D cylinders at Reynolds number equal to 90,000. Finally, three different LES turbulence models are combined with the standard MRT-LBM method, where different finite difference schemes are used to solve Reynolds stress tensor which is different from the traditional one. Through the direct acoustic numerical simulation of NACA0012 airfoil at Reynolds number equal to 200,000, the effects of Smagorinsky models and Wall-adapting local eddy-viscosity (WALE) model on aerodynamic noise prediction are compared and analyzed. Overall, the proposed methodology is shown to be appropriate for predicting the aerodynamic noise at low Mach number and can successfully simulate the generation and propagation of far field acoustics.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 7","pages":"1250-1275"},"PeriodicalIF":1.8,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140370669","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 data-driven turbulence modeling for the Reynolds stress tensor transport equation 雷诺应力张量传输方程的数据驱动湍流建模

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-03-26 DOI: 10.1002/fld.5284

Matheus S. S. Macedo, Matheus A. Cruz, Bernardo P. Brener, Roney L. Thompson

{"title":"A data-driven turbulence modeling for the Reynolds stress tensor transport equation","authors":"Matheus S. S. Macedo, Matheus A. Cruz, Bernardo P. Brener, Roney L. Thompson","doi":"10.1002/fld.5284","DOIUrl":"10.1002/fld.5284","url":null,"abstract":"The long lasting demand for better turbulence models and the still prohibitively computational cost of high-fidelity fluid dynamics simulations, like direct numerical simulations and large eddy simulations, have led to a rising interest in coupling available high-fidelity datasets and popular, yet limited, Reynolds averaged Navier–Stokes simulations through machine learning (ML) techniques. Many of the recent advances used the Reynolds stress tensor or, less frequently, the Reynolds force vector as the target for these corrections. In the present work, we considered an unexplored strategy, namely to use the modeled terms of the Reynolds stress transport equation as the target for the ML predictions, employing a neural network approach. After that, we solve the coupled set of governing equations to obtain the mean velocity field. We apply this strategy to solve the flow through a square duct. The obtained results consistently recover the secondary flow, which is not present in the baseline simulations that used the <math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>κ</mi>\u0000 <mo>−</mo>\u0000 <mi>ϵ</mi>\u0000 </mrow>\u0000 <annotation>$$ kappa -epsilon $$</annotation>\u0000 </semantics></math> model. The results were compared with other approaches of the literature, showing a path that can be useful in the seek of more universal models in turbulence.","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 7","pages":"1194-1214"},"PeriodicalIF":1.8,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140303186","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

Development of a cascaded lattice Boltzmann model for two-layer shallow water flows 开发双层浅水流动的级联晶格玻尔兹曼模型

IF 1.8 4区工程技术

International Journal for Numerical Methods in Fluids Pub Date : 2024-03-26 DOI: 10.1002/fld.5288

Silvia Di Francesco, Sara Venturi, Jessica Padrone, Antonio Agresta

{"title":"Development of a cascaded lattice Boltzmann model for two-layer shallow water flows","authors":"Silvia Di Francesco, Sara Venturi, Jessica Padrone, Antonio Agresta","doi":"10.1002/fld.5288","DOIUrl":"10.1002/fld.5288","url":null,"abstract":"<div>\u0000 \u0000 Many environmental phenomena, such as flows in rivers or in coastal region can be characterised by means of the ‘shallow approach’. A multi-layer scheme allows to extend it to density layered shallow water flows (e.g., gravity currents). Although a variety of models allowing numerical investigation of single and multi-layer shallow water flows, based on continuum and particle approaches, have been widely discussed, there are still some computational aspects that need further investigation. Focusing on the Lattice Boltzmann models (LBM), available multi-layer models generally use the standard linear collision operator (CO). In this work we adopt a multi relaxation time (MRT) cascaded collision operator to develop a two-layered liquid Lattice-Boltzmann model (CaLB-2). Specifically, the model solves the shallow water equations, taking into account two separate sets of particle distribution function (PDF), one for each layer, solved separately. Layers are connected through coupling terms, defined as external forces that model the mutual actions between the two layers. The model is validated through comparisons with experimental and numerical results from test cases available in literature. First results are very promising, highlighting a good correspondence between simulation results and literature benchmarks.\u0000 </div>","PeriodicalId":50348,"journal":{"name":"International Journal for Numerical Methods in Fluids","volume":"96 7","pages":"1230-1249"},"PeriodicalIF":1.8,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140301794","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