Computers & Fluids最新文献

A structurally compatible forcing scheme for three-dimensional cumulant lattice Boltzmann method 三维累积量晶格玻尔兹曼法的结构相容强迫格式

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-26 DOI: 10.1016/j.compfluid.2025.106762

Jie Kang, Dongyin Wu

{"title":"A structurally compatible forcing scheme for three-dimensional cumulant lattice Boltzmann method","authors":"Jie Kang, Dongyin Wu","doi":"10.1016/j.compfluid.2025.106762","DOIUrl":"10.1016/j.compfluid.2025.106762","url":null,"abstract":"<div><div>This study introduces a structurally compatible forcing scheme for the three-dimensional cumulant lattice Boltzmann method (LBM) based on the D3Q27 velocity set, and successfully integrates the pseudopotential model into the three-dimensional cumulant LBM framework. Asymptotic analysis confirms the scheme’s capability to recover the macroscopic Navier–Stokes equations, demonstrating its compatibility with the cumulant LBM structure. Numerical experiments reveal that under constant external force fields, the proposed scheme reduces the relative errors from 2.44<span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup></mrow></math></span> (the conventional scheme) to 4.09<span><math><mrow><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>8</mn></mrow></msup></mrow></math></span> by accounting for high-order cumulants in the force coupling. Notably, the integration of the pseudopotential model via this scheme effectively suppresses anisotropic distortions observed in the traditional scheme, reducing the maximum dimensionless radial deviation of the droplet from 7.21% to 0.11%. Furthermore, wettability simulations confirm the reliability of the scheme, showing a strong linear correlation (<span><math><mrow><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>></mo><mn>0</mn><mo>.</mo><mn>99</mn></mrow></math></span>) between the contact angle and the adhesive parameter<!--> <span><math><msub><mrow><mi>G</mi></mrow><mrow><mi>w</mi></mrow></msub></math></span>. Additionally, droplet collision tests validate its robustness in dynamic scenarios. This work develops a structurally compatible forcing scheme for the three-dimensional cumulant LBM, which modifies the force effects on high-order cumulants. The proposed scheme maintains the cumulant-based LBM structure while enabling robust simulations across diverse flow regimes, from single-phase flow to dynamic droplet collision.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106762"},"PeriodicalIF":2.5,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144712933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Three-dimensional SPH modeling of brittle fracture under hydrodynamic loading 水动力作用下脆性断裂的三维SPH模型

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-07-25 DOI: 10.1016/j.compfluid.2025.106763

Vishabjeet Singh , Chong Peng , Md Rushdie Ibne Islam

引用次数: 0

Non-intrusive model reduction of advection-dominated hyperbolic problems using neural network shift augmented manifold transformation 利用神经网络移位增广流形变换对平流控制的双曲型问题进行非侵入式模型约简

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-07-25 DOI: 10.1016/j.compfluid.2025.106758

Harshith Gowrachari , Nicola Demo , Giovanni Stabile , Gianluigi Rozza

{"title":"Non-intrusive model reduction of advection-dominated hyperbolic problems using neural network shift augmented manifold transformation","authors":"Harshith Gowrachari , Nicola Demo , Giovanni Stabile , Gianluigi Rozza","doi":"10.1016/j.compfluid.2025.106758","DOIUrl":"10.1016/j.compfluid.2025.106758","url":null,"abstract":"<div><div>Advection-dominated problems are predominantly noticed in nature, engineering systems, and various industrial processes. Traditional linear compression methods, such as proper orthogonal decomposition (POD) and reduced basis (RB) methods are ill-suited for these problems, due to slow Kolmogorov <em>n</em>-width decay. This results in inefficient and inaccurate reduced order models (ROMs). There are few non-linear approaches to accelerate the Kolmogorov <em>n</em>-width decay. In this work, we use a neural network shift augmented transformation technique that employs automatic shift detection. This approach leverages a deep-learning framework to derive a parameter-dependent mapping between the original manifold <span><math><mi>M</mi></math></span> and the transformed manifold <span><math><mover><mrow><mi>M</mi></mrow><mrow><mo>̃</mo></mrow></mover></math></span>. We apply a linear compression method to obtain a low-dimensional linear approximation subspace of the transformed manifold <span><math><mover><mrow><mi>M</mi></mrow><mrow><mo>̃</mo></mrow></mover></math></span>. Furthermore, we construct non-intrusive reduced order models on the resulting transformed linear approximation subspace and employ automatic shift detection for predictions in the online stage. We propose a complete framework, the neural network shift-augmented proper orthogonal decomposition-based reduced order model (NNsPOD-ROM) algorithm, comprising both offline and online stages for model reduction of advection-dominated problems. We test our proposed methodology on numerous experiments to evaluate its performance on the 1D linear advection equation, a higher order method benchmark case - the 2D isentropic convective vortex, and 2D two-phase flow.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106758"},"PeriodicalIF":3.0,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 around square, rounded, and round-convex cylinders at Reynolds numbers 20 to 22,000 在雷诺数为20到22000的方形、圆形和圆凸圆柱体周围流动

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-24 DOI: 10.1016/j.compfluid.2025.106771

Haotian Dong , Shuting Fang , Xiaoqing Du

{"title":"Flow around square, rounded, and round-convex cylinders at Reynolds numbers 20 to 22,000","authors":"Haotian Dong , Shuting Fang , Xiaoqing Du","doi":"10.1016/j.compfluid.2025.106771","DOIUrl":"10.1016/j.compfluid.2025.106771","url":null,"abstract":"<div><div>Flow around a square-like cylinder with round corners at a radius <em>R</em> = <em>B</em>/7 (<em>B</em>: nominal side length) and round sides at a radius <em>K</em> = <em>B</em> were numerically investigated at Reynolds numbers <em>Re</em> = 20 to 22,000. The <em>Re</em>-dependence of flow-induced loading and flow features of this “round-convex” cylinder was compared with square and rounded cylinders. Compared with the square and rounded cylinders, the round-convex cross-section has a smaller and declining drag, lower fluctuating loads, and a weaker vortex shedding from <em>Re</em> = 1000 to 22,000, showing distinct Reynolds number effects. A steady regime at <em>Re</em> = 20 and 45, a 2D regime at <em>Re</em> = 100 and 200, a 3D regime at <em>Re</em> = 300, 500, and 1000, and a turbulent regime at <em>Re</em> = 3900, 10,000, and 22,000 are identified for the round-convex and rounded cylinders, while a 3D flow is observed at <em>Re</em> = 300 for the square cylinder. The flow separation shifts from the rear corner to the front corner at <em>Re</em> = 200 and 300 for the square and rounded cylinders, respectively, while the separation point gradually moves to the middle of lateral sides for round-convex cylinders, which is similar to a circular cylinder.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106771"},"PeriodicalIF":2.5,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Benchmarking convolutional neural network and graph neural network based surrogate models on a real-world car external aerodynamics dataset 在真实汽车外部空气动力学数据集上对基于卷积神经网络和图形神经网络的代理模型进行基准测试

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-23 DOI: 10.1016/j.compfluid.2025.106760

Sam Jacob Jacob , Markus Mrosek , Carsten Othmer , Harald Köstler

{"title":"Benchmarking convolutional neural network and graph neural network based surrogate models on a real-world car external aerodynamics dataset","authors":"Sam Jacob Jacob , Markus Mrosek , Carsten Othmer , Harald Köstler","doi":"10.1016/j.compfluid.2025.106760","DOIUrl":"10.1016/j.compfluid.2025.106760","url":null,"abstract":"<div><div>Aerodynamic optimization is crucial for developing eco-friendly, aerodynamic, and stylish cars, which requires close collaboration between aerodynamicists and stylists, a collaboration impaired by the time-consuming nature of aerodynamic simulations. Surrogate models offer a viable solution to reduce this overhead, but they are untested in real-world aerodynamic datasets. We present a comparative evaluation of two surrogate modeling approaches for predicting drag on a real-world dataset: a Convolutional Neural Network (CNN) model that uses a signed distance field as input and a commercial tool based on Graph Neural Networks (GNN) that directly processes a surface mesh. In contrast to previous studies based on datasets created from parameterized geometries, our dataset comprises 343 geometries derived from 32 baseline vehicle geometries across five distinct car projects, reflecting the diverse, free-form modifications encountered in the typical vehicle development process. Our results show that the CNN-based method achieves a mean absolute error of 2.3 drag counts, while the GNN-based method achieves 3.8. Both methods achieve approximately 77% accuracy in predicting the direction of drag change relative to the baseline geometry. While both methods effectively capture the broader trends between baseline groups (set of samples derived from a single baseline geometry), they struggle to varying extents in capturing the finer intra-baseline group variations. In summary, our findings suggest that aerodynamicists can effectively use both methods to predict drag in under two minutes, which is at least 600 times faster than performing a simulation. However, there remains room for improvement in capturing the finer details of the geometry.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106760"},"PeriodicalIF":2.5,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Enhanced simulation techniques in predicting sonic boom loudness using CFD 基于CFD预测音爆响度的改进模拟技术

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-23 DOI: 10.1016/j.compfluid.2025.106759

S. Neuhoff, C. Ashby, J. Housman, J. Duensing

引用次数: 0

Mixture-conservative temperature-based Baer–Nunziato solver for efficient full-disequilibrium simulations of real fluids 基于混合保守温度的真实流体全不平衡模拟的Baer-Nunziato求解器

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-23 DOI: 10.1016/j.compfluid.2025.106761

G. Sirianni , B. Re , R. Abgrall

引用次数: 0

Localized implicit iterative shifting to improve particle distribution in Smoothed Particle Hydrodynamics 局部隐式迭代移位改善光滑粒子流体力学中粒子分布

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-22 DOI: 10.1016/j.compfluid.2025.106753

Mohamad Amin Ghazi , Renato Vacondio , Jean-Christophe Marongiu

{"title":"Localized implicit iterative shifting to improve particle distribution in Smoothed Particle Hydrodynamics","authors":"Mohamad Amin Ghazi , Renato Vacondio , Jean-Christophe Marongiu","doi":"10.1016/j.compfluid.2025.106753","DOIUrl":"10.1016/j.compfluid.2025.106753","url":null,"abstract":"<div><div>This study presents a novel Implicit Iterative Particle Shifting method designed to enhance the accuracy of Smoothed Particle Hydrodynamics (SPH) simulations by improving particle distribution through the solution of a linear system of equations. The proposed approach addresses key limitations of existing techniques, namely distribution instability and lack of control over maximum particle displacement by accounting for the contribution of neighboring particles on a given particle when constructing the linear system. The method also imposes a constraint on the shifting magnitude, allowing for better control of particle movement and improved distribution stability also in presence of free surface. To reduce computational cost, a localization procedure has been introduced that restricts particle shifting to regions where it is necessary. The effectiveness of the method is demonstrated through a series of benchmark tests, including the Taylor–Green vortex, a moving square box, an oscillating droplet, and a dam break flow. The results show substantial improvements in the uniformity of the particle distribution, computational efficiency, and simulation accuracy compared to established methods.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106753"},"PeriodicalIF":2.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Improved State Estimation for turbulent flows combining Ensemble Data Assimilation and Machine Learning 结合集成数据同化和机器学习的湍流状态估计改进

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-22 DOI: 10.1016/j.compfluid.2025.106757

Miguel M. Valero, Marcello Meldi

{"title":"Improved State Estimation for turbulent flows combining Ensemble Data Assimilation and Machine Learning","authors":"Miguel M. Valero, Marcello Meldi","doi":"10.1016/j.compfluid.2025.106757","DOIUrl":"10.1016/j.compfluid.2025.106757","url":null,"abstract":"<div><div>A novel strategy is proposed to improve the accuracy of state estimation and the reconstruction from low-fidelity models and sparse data from sensors. This strategy combines ensemble Data Assimilation (DA) and Machine Learning (ML) tools, exploiting their complementary features. ML techniques rely on the data produced by DA methods during analysis phases to train physics-informed corrective algorithms, which are then coupled with the low-fidelity models when data from sensors is unavailable. The methodology is validated via the analysis of the turbulent plane channel flow test case for <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>≈</mo><mn>550</mn></mrow></math></span>. Here, the low-fidelity model consists of coarse-grained simulations coupled with the Immersed Boundary Method (IBM), while observation is sampled by a highly refined body-fitted calculation. The analysis demonstrates the capabilities of the algorithm based on DA and ML to accurately predict the flow features with significantly reduced computational costs. This approach exhibits potential for future synergistic applications of DA and ML, leveraging the robustness and efficiency of ML models alongside the physical interpretability ensured by DA algorithms.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106757"},"PeriodicalIF":2.5,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Introduction of dispersive effects and treatment of horizontally moving pressurized regions in a semi-implicit fluid–structure interaction model 介绍了半隐式流固耦合模型中水平移动受压区域的色散效应和处理方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-07-21 DOI: 10.1016/j.compfluid.2025.106756

Cristian Brutto , Michael Dumbser , Martin Parisot , Mario Ricchiuto

{"title":"Introduction of dispersive effects and treatment of horizontally moving pressurized regions in a semi-implicit fluid–structure interaction model","authors":"Cristian Brutto , Michael Dumbser , Martin Parisot , Mario Ricchiuto","doi":"10.1016/j.compfluid.2025.106756","DOIUrl":"10.1016/j.compfluid.2025.106756","url":null,"abstract":"<div><div>In geophysical fluid structure interaction problems with moving free surface, large relative motions between the fluid and solid domains generate not only physical waves on the free surface, but may also trigger numerical instabilities. This is also the case in models for moving floating structures above water. Since the governing equations change type from hyperbolic below the free surface to elliptic below the moving floating object within the cells of the computational domain, the horizontal motion may exhibit a numerical instability that is not observed solely with the vertical heave motion. When a ship enters a new cell, the pressure at the bow increases and decreases sharply, leading to oscillations that can create an unphysical void below the vessel. After examining the origin of the problem, several measures were taken at the discrete level to reduce these spurious oscillations. All of these modifications were effective in controlling the oscillations, making numerical simulations with horizontal motion of moving floating objects more robust, stable and accurate.</div><div>To enhance the range of application of the model, we also include some additional weakly dispersive terms. The same study is then performed in presence of these non-hydrostatic effects, showing a reliable and robust prediction of the interaction of moving bodies interacting with hydrostatic and non-hydrostatic waves.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106756"},"PeriodicalIF":2.5,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144695182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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