Computers & Fluids最新文献_第10页

An Eulerian-based immersed boundary method using direct forcing on piecewise linear constructed interface 基于欧拉的分段线性构造界面直接强迫浸入边界法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-23 DOI: 10.1016/j.compfluid.2025.106727

Spencer Schwartz, Yue Ling

{"title":"An Eulerian-based immersed boundary method using direct forcing on piecewise linear constructed interface","authors":"Spencer Schwartz, Yue Ling","doi":"10.1016/j.compfluid.2025.106727","DOIUrl":"10.1016/j.compfluid.2025.106727","url":null,"abstract":"<div><div>We present a novel Eulerian-based Immersed Reconstructed Boundary Method (IRBM) for resolving fluid interactions with moving solids. The immersed solid body is represented by a scalar field of solid volume fraction, and the motion of the solid is achieved by advecting the solid volume fraction. The solid–fluid interface is reconstructed using the piecewise linear interface construction (PLIC), and the penalty force is applied at the centroid of the reconstructed interface using an iterative multi-direct forcing approach, to ensure the no-slip boundary condition. This method is implemented in the open-source solver <em>Basilisk</em>, which uses an adaptive quadtree/octree mesh for spatial discretization. The method is validated through simulations of several 2D and 3D test cases, including 2D flow over stationary and oscillating cylinders and 3D flow over a stationary sphere. The simulation results are compared with previous experiments, simulations using body-fitted meshes, and other numerical methods on non-conforming meshes, such as the immersed boundary method and embedded boundary method, showing good agreement in all cases tested.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106727"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514079","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

Droplet dynamics in capillary parallel plate channel 毛细管平行平板通道中的液滴动力学

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-23 DOI: 10.1016/j.compfluid.2025.106728

Damien Thomas , Stéphanie Lacour , Stéphane Zaleski

{"title":"Droplet dynamics in capillary parallel plate channel","authors":"Damien Thomas , Stéphanie Lacour , Stéphane Zaleski","doi":"10.1016/j.compfluid.2025.106728","DOIUrl":"10.1016/j.compfluid.2025.106728","url":null,"abstract":"<div><div>Sprays are more effective in dissipating heat compared to forced air convection. However, in heat exchangers, water films can block airflow through the fins during spray injection. This obstruction leads to a reduction in heat transfer and an increase in pressure drop. To address this issue, enhanced fins are essential to maintain a high heat transfer rate during spray cooling. Consequently, the study investigates the clogging processes related to the water films generated by sprays.</div><div>Numerical methods using the Volume Of Fluid (VOF) approach were employed to model the water–air interface of a droplet crossing a heat exchanger. The heat exchanger is modeled as a channel with two parallel plates as an embedded boundary. A variable-size droplet, representing an aggregate of spray droplets at the channel entry, is introduced and slides down the plates.</div><div>The outcome of the droplet penetration depends on factors such as the plate gap width, the droplet size, and the contact angle. In this context, overcoming an energy barrier is crucial for droplet penetration. The energy required, influenced by capillarity, makes hydrophobic surfaces challenging to penetrate. However, hydrophilic surfaces complicate droplet exit. Large droplets tend to break down into smaller ones during penetration. The crossing time, of similar magnitude for both hydrophobic and hydrophilic surfaces, depends mainly on the aspect ratio between the droplet diameter and the gap width. The drop break-up and the crossing time are thoroughly analyzed to identify the delicate balance of parameters essential for preventing channel clogging.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106728"},"PeriodicalIF":2.5,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571307","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

Embedded LES boundary conditions for shear dominated flows 剪切主导流动的嵌入式LES边界条件

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-21 DOI: 10.1016/j.compfluid.2025.106729

J. Borgelt, M. Meinke, W. Schröder

{"title":"Embedded LES boundary conditions for shear dominated flows","authors":"J. Borgelt, M. Meinke, W. Schröder","doi":"10.1016/j.compfluid.2025.106729","DOIUrl":"10.1016/j.compfluid.2025.106729","url":null,"abstract":"<div><div>An embedded LES method is introduced which combines the efficiency of Reynolds-averaged Navier–Stokes (RANS) models with the turbulence resolving capabilities of large-eddy simulation (LES). The turbulent scale resolved embedded LES region is reduced to a region of interest, for which boundary conditions are formulated from a preliminary RANS solution. The method is validated for simulations of detached flow in which the embedded LES region is reduced to the separation region. The outflow is placed in the high-vorticity region of the separation flow in which recirculations with local negative streamwise velocities occur. For the outflow boundary a novel Navier–Stokes characteristic boundary condition which uses information of the RANS solution is presented. The formulation allows the simulation of reversed flow and ensures well-posedness of the problem with minimal wave reflections at the exit of the domain. The outflow boundary condition is combined with a synthetic turbulence generation method employed to generate the turbulent energy spectrum at the inflow of the embedded LES region. At the wall-parallel or tangential zonal interface the embedded LES uses the entering and exiting mass flux of the preliminary RANS solution as a boundary condition. The quality of the presented method is shown for the separating flow over a curved backward-facing step with non-zero mass flux over the tangential interface.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106729"},"PeriodicalIF":2.5,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471885","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

Wake dynamics of two side-by-side rectangular cylinders 两个并排矩形圆柱体的尾迹动力学

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-18 DOI: 10.1016/j.compfluid.2025.106734

Dayu Zhu, Hongshan Lin, Yuan Ma, Renjie Jiang

引用次数: 0

Microscopic mechanism model of eddy flow and nonlinear flow characteristic analysis in rough rock fractures based on lattice Boltzmann method 基于晶格玻尔兹曼方法的粗糙岩石裂隙涡流微观机理模型及非线性流动特性分析

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-18 DOI: 10.1016/j.compfluid.2025.106735

Changning Mi , Jianping Zuo

{"title":"Microscopic mechanism model of eddy flow and nonlinear flow characteristic analysis in rough rock fractures based on lattice Boltzmann method","authors":"Changning Mi , Jianping Zuo","doi":"10.1016/j.compfluid.2025.106735","DOIUrl":"10.1016/j.compfluid.2025.106735","url":null,"abstract":"<div><div>Nonlinear flow through rough rock fractures is studied using theoretical analysis and numerical simulation. Based on the incompressible Navier–Stokes equations with explicit velocity field decomposition, we introduce vortex momentum and derive an approximate inertial term via perturbation expansion. A novel Laminar–Eddy (LE) microscopic flow model is thereby proposed to elucidate the fundamental microscale mechanisms of nonlinear flow. Using a self-developed GPU-parallelized lattice Boltzmann solver, we simulate fluid flow through nine synthetic fractures with systematically varied fractal roughness and apertures under a series of imposed pressure gradients. The results show that the flow rate–pressure gradient relationship deviates from linearity as pressure increases. Flow field visualization reveals that eddy formation and growth near rough walls are the key factors behind nonlinear macroscopic behavior and complex velocity distributions. Analysis of the normalized transmissivity versus Reynolds number demonstrates the transition from viscous to inertial flow regimes. These findings clarify the micro-mechanisms behind nonlinear fracture flow, providing insight beyond traditional empirical models and guiding future permeability models in complex fracture networks.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"300 ","pages":"Article 106735"},"PeriodicalIF":2.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144517879","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

Numerical simulation of dynamic wetting in ternary fluids flows on curved substrates 弯曲基底上三元流体动态润湿的数值模拟

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-18 DOI: 10.1016/j.compfluid.2025.106724

Chun-Yu Zhang , Jian-Yu Lin , Hao-Ran Liu

引用次数: 0

Immersed boundary formulation for complex geometries in hypersonic flows: Application to atmospheric reentry 高超声速复杂几何流的浸入边界公式：在大气再入中的应用

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-16 DOI: 10.1016/j.compfluid.2025.106715

Iko Midani , Valentin Ledermann , Eddy Constant , Martin Spel , Laurent Stainier , Pierre Boivin , Julien Favier

{"title":"Immersed boundary formulation for complex geometries in hypersonic flows: Application to atmospheric reentry","authors":"Iko Midani , Valentin Ledermann , Eddy Constant , Martin Spel , Laurent Stainier , Pierre Boivin , Julien Favier","doi":"10.1016/j.compfluid.2025.106715","DOIUrl":"10.1016/j.compfluid.2025.106715","url":null,"abstract":"<div><div>This article discusses the challenges of modeling atmospheric reentry using computational fluid dynamics (CFD) due to its complexity and practical industrial applications. Ablation phenomena caused by high energy make it difficult and time-consuming to use a “high-fidelity” CFD method to accurately measure forces and heat flux. As a result, methods based on Newton’s theory are used to model aerodynamic forces, incorporating statistical correlations from CFD results to estimate heat fluxes. However, these methods sacrifice accuracy for CPU and engineering time and have difficulty representing realistic physics when complex phenomena occur, such as shock interactions. To bridge the gap between approximate and high-fidelity methods, we propose a new approach using an automatic grid generation method of the octree Cartesian type coupled to a solver solving Euler’s equations. To apply the boundary condition accurately we compared two immersed boundary methods: a diffuse interface method and a sharp interface method under hypersonic flow configurations. We present a comparative study of these two formulations on verification and validation phases, including an academic test case and an industrial case on a real reentry spacecraft. The novelty lies in applying these methods to complex cases involving strong discontinuities (attached shocks). After concluding this comparative study, we demonstrate that with adapted formulations and an optimized approach, IB methods can handle complex geometries typical of atmospheric reentry.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106715"},"PeriodicalIF":2.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144364495","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

On the effectiveness of fine-grain parallel linear iterations for computational aerodynamics on structured grids for graphics processing units 图形处理单元结构网格上细粒度并行线性迭代计算空气动力学的有效性

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-16 DOI: 10.1016/j.compfluid.2025.106714

Aditya Kashi , Siva Nadarajah

引用次数: 0

A deep-neural-network accelerated precursor-based method for atmospheric boundary layers 基于深度神经网络的大气边界层加速前兆方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-14 DOI: 10.1016/j.compfluid.2025.106731

Ke Li, Ruifang Shen, Bowen Yan, Qingshan Yang, Jiahao Yang

{"title":"A deep-neural-network accelerated precursor-based method for atmospheric boundary layers","authors":"Ke Li, Ruifang Shen, Bowen Yan, Qingshan Yang, Jiahao Yang","doi":"10.1016/j.compfluid.2025.106731","DOIUrl":"10.1016/j.compfluid.2025.106731","url":null,"abstract":"<div><div>The use of the precursor simulation method to generate inflowing atmospheric boundary layer turbulence is confronted with the problem of excessive computational load due to the excessive number of grids in the reference flow field. For this reason, this paper proposes an inflow model via a spatial and temporal resolution enhancement method based on deep neural networks. It can deduce the high-resolution computational domain inlet used in formal calculations based on the low-resolution reference flow field, thus achieving a more efficient generation of atmospheric boundary layer turbulence. This method includes two key modules: the Temporal Resolution Enhancement Module (TREM) and the Spatial Resolution Enhancement Module (SREM). By evaluating the effects of autoencoders with different compression ratios and time series prediction models, the optimal performance of TREM has been studied to achieve the best effect of temporal resolution enhancement. Meanwhile, the SREM was constructed by using a high performance autoencoder and combined with the TREM to form the spatial and temporal resolution enhancement model. By simulating the turbulent flow field of an atmospheric boundary layer wind tunnel, the results show that after using the spatial and temporal resolution enhancement method, the turbulent data has been improved in statistical characteristics such as the mean wind speed, turbulence intensity, power spectrum of fluctuating wind speed and spanwise spatial energy spectrum, as well as in the flow field structure, approaching the results of large eddy simulations (LES) with high spatial and temporal resolution. Compared with the traditional precursor simulation method, the generation speed is approximately 12 times faster.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106731"},"PeriodicalIF":2.5,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144364500","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

Computational fluid dynamics simulations of suspensions of spherical particles using tensorial constitutive equations 使用张量本构方程的球颗粒悬浮液计算流体动力学模拟

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-13 DOI: 10.1016/j.compfluid.2025.106704

Hugo A. Castillo-Sánchez , Jurriaan Gillissen , Roberto Lange , Antonio Castelo

{"title":"Computational fluid dynamics simulations of suspensions of spherical particles using tensorial constitutive equations","authors":"Hugo A. Castillo-Sánchez , Jurriaan Gillissen , Roberto Lange , Antonio Castelo","doi":"10.1016/j.compfluid.2025.106704","DOIUrl":"10.1016/j.compfluid.2025.106704","url":null,"abstract":"<div><div>In the present work, we implement full tensorial constitutive equations for suspensions of spherical particles into the <em>HiGFlow</em> system, which is a recently developed Computational Fluid Dynamics (CFD) software that is able to simulate Newtonian, Generalised-Newtonian and viscoelastic flows using finite differences in tree-based grids. We provide here a brief introduction to each of the implemented constitutive equations that were developed to describe the rheological behaviour of rate-independent suspensions homogeneous flows. We tested our solvers by carrying out simulations of these models in three relevant flow configurations (simple shear, shear reversal and oscillatory flows), and our simulation results were validated by comparing them with results reported in the literature and with those predicted by the <em>foam-extend</em> system, a community-driven fork of the popular <em>OpenFOAM</em> open source library for CFD. Lastly, we carry out simulations in a geometry in which these models have not been tested before; the lid-driven cavity. For this case, we report here novel results, where we offer an in-depth analysis of the rheological behaviour of the suspension in the cavity flow with weak inertia, including contour maps of both the stress and second-order orientation moment tensors that assist the reader in visualising the particle dynamics. A direct comparison of our cavity results with simulations obtained using the FENE-P viscoelastic constitutive model is also provided, where we found that while the magnitude of the value of the particle normal stress <span><math><msub><mrow><mi>τ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></math></span> is amplified in compression regions, the viscoelastic normal stress <span><math><msub><mrow><mi>σ</mi></mrow><mrow><mi>x</mi><mi>x</mi></mrow></msub></math></span> is more dominant in extensional regions.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106704"},"PeriodicalIF":2.5,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313238","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