Computers & Fluids最新文献_第4页

A hardware locality-informed dynamic load balancing for a p-adaptive local discontinuous Galerkin LES solver p-自适应局部不连续Galerkin LES解算器的硬件位置通知动态负载平衡

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-11 DOI: 10.1016/j.compfluid.2025.106810

Paolo Valvo, Antonella Abbà

引用次数: 0

Near-body mesh adaptation for transitional flows using OVERFLOW 用OVERFLOW自适应过渡流的近体网格

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-10 DOI: 10.1016/j.compfluid.2025.106831

B. Venkatachari , M. Donello , J. Derlaga , M. Choudhari

{"title":"Near-body mesh adaptation for transitional flows using OVERFLOW","authors":"B. Venkatachari , M. Donello , J. Derlaga , M. Choudhari","doi":"10.1016/j.compfluid.2025.106831","DOIUrl":"10.1016/j.compfluid.2025.106831","url":null,"abstract":"<div><div>Accurate modeling of boundary-layer transition is an important aspect of developing greener air transport technologies. In that regard, transition models based on auxiliary transport equations offer a robust approach that is easily integrated into the Reynolds-averaged Navier-Stokes (RANS) solvers. Recent workshops under NATO and AIAA have identified the verification of transport-equations-based transition modeling as a critical aspect of reducing the scatter between the predictions of different CFD codes. Follow-on work has highlighted the need for highly dense grids to achieve an asymptotic convergence of transition related flow metrics. The present work examines the role of automatic near-body mesh adaptation in the NASA OVERFLOW CFD solver to enable verification studies in an efficient manner, and for establishing best practices for designing grids for the RANS-based transition models. We propose a sensor function based on a suitably augmented form of the second undivided difference of vorticity magnitude for error-based mesh adaptation of transitional flows. Directly relevant to the Langtry-Menter <span><math><mrow><mi>γ</mi><mo>−</mo><mi>R</mi><msub><mi>e</mi><mrow><mi>θ</mi><mi>t</mi></mrow></msub><mspace></mspace></mrow></math></span>transition model, the proposed sensor function is evaluated in the context of canonical configurations consisting of the flat plate and the S809 and NLR-7301 airfoils. The efficacy of the mesh adaptation approach is assessed for flow conditions involving multiple transition scenarios such as natural transition, separation-induced transition, and shock-induced transition. The results indicate that the predicted flow metrics based on the adapted meshes approach the reference predictions based on hand-crafted and uniformly refined meshes, while yielding modest yet significant savings in total grid count. Areas for further improvement in the grid adaptation methodology are also highlighted.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"302 ","pages":"Article 106831"},"PeriodicalIF":3.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107145","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

Benchmark study of unsteady flow inside a square lid driven cavity 方盖驱动腔内非定常流场的基准研究

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-10 DOI: 10.1016/j.compfluid.2025.106812

Aditi Sengupta , Abhinav Prakash , Vajjala K. Suman , Tapan K. Sengupta

{"title":"Benchmark study of unsteady flow inside a square lid driven cavity","authors":"Aditi Sengupta , Abhinav Prakash , Vajjala K. Suman , Tapan K. Sengupta","doi":"10.1016/j.compfluid.2025.106812","DOIUrl":"10.1016/j.compfluid.2025.106812","url":null,"abstract":"<div><div>The present work provides a time-resolved benchmark dataset for simulating supercritical, unsteady flow inside a square lid-driven cavity (LDC). To explain the role of fidelity of the computations and that of the numerical error in triggering instabilities, the flow is computed with three time-steps. This effort is substantiated with the use of an error dynamics equation, developed to model the physical processes in the Navier–Stokes equation (NSE), using global spectral analysis (GSA) of a model convection–diffusion equation. The error is found to be diffusion-dominated for this particular class of flows. There exists lack of consensus regarding the critical value of Reynolds number (<span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span>) beyond which flow becomes unsteady for the square LDC. The study aims to bridge this gap by devoting a detailed discussion on the onset of unsteadiness by simulating LDC for <span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span> in the range of 7900 to 8900. Furthermore, the first Hopf bifurcation that is typically observed for LDC is quantified, laying the foundation for development of data-driven machine learning alternatives to expensive high fidelity simulations.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"302 ","pages":"Article 106812"},"PeriodicalIF":3.0,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145047477","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

A numerical method based on quasi-Lagrangian Voronoi cells for two-phase flows with large density contrast 基于准拉格朗日Voronoi单元的大密度对比两相流数值计算方法

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-04 DOI: 10.1016/j.compfluid.2025.106813

Ondřej Kincl , Ilya Peshkov , Walter Boscheri

引用次数: 0

A joint parameter-state estimation framework using POD-Galerkin projected reduced order model and 3DVar data assimilation 基于POD-Galerkin投影降阶模型和3DVar数据同化的参数状态联合估计框架

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-03 DOI: 10.1016/j.compfluid.2025.106815

Chuqiao Dai , Di Yang , Chunyu Zhang , Peng Ding , Chengjie Duan , Juqing Song

{"title":"A joint parameter-state estimation framework using POD-Galerkin projected reduced order model and 3DVar data assimilation","authors":"Chuqiao Dai , Di Yang , Chunyu Zhang , Peng Ding , Chengjie Duan , Juqing Song","doi":"10.1016/j.compfluid.2025.106815","DOIUrl":"10.1016/j.compfluid.2025.106815","url":null,"abstract":"<div><div>Reduced-order models (ROMs) provide a fast and efficient approach to approximate full-order numerical models by capturing their essential dynamics. However, uncertainties in boundary conditions can lead to noticeable discrepancies between ROM simulations and real-world behavior. To address this challenge, this study introduces a novel framework that jointly corrects parameters and states by integrating ROMs with three-dimensional variational data assimilation (3D-Var). The framework operates in two sequential stages: a parameter estimation stage and a state reconstruction stage. Optimal parameter estimates are firstly derived to drive the ROM, generating optimal background information for the subsequent state reconstruction. A background error covariance matrix is computed from snapshots generating the ROM, significantly enhancing the reliability of the online data assimilation process. This study further explores the influence of sensor placement, measurement noise, and the number of measurement points on assimilation performance. Guidelines for optimal sensor placement are provided, along with an analysis of the prediction capability over extended parameter ranges. This framework offers a robust solution for enhancing the fidelity of ROMs in practical applications.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"302 ","pages":"Article 106815"},"PeriodicalIF":3.0,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145046994","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

A comprehensive numerical study of transient two-phase flow for slug capturing simulations 段塞捕获模拟瞬态两相流的综合数值研究

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-03 DOI: 10.1016/j.compfluid.2025.106814

Carina Nogueira Sondermann , Raphael Viggiano , Felipe Bastos de Freitas Rachid , Gustavo Cesar Rachid Bodstein , Eduardo Pereyra

引用次数: 0

Hybrid AutoEncoder/Galerkin approach for nonlinear reduced order modelling 非线性降阶建模的混合自编码器/伽辽金方法

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-09-02 DOI: 10.1016/j.compfluid.2025.106811

Nicolas Lepage , Samir Beneddine , Camilla Fiorini , Iraj Mortazavi , Denis Sipp , Nicolas Thome

{"title":"Hybrid AutoEncoder/Galerkin approach for nonlinear reduced order modelling","authors":"Nicolas Lepage , Samir Beneddine , Camilla Fiorini , Iraj Mortazavi , Denis Sipp , Nicolas Thome","doi":"10.1016/j.compfluid.2025.106811","DOIUrl":"10.1016/j.compfluid.2025.106811","url":null,"abstract":"<div><div>This paper presents a novel nonlinear Reduced Order Model (ROM) that combines Proper Orthogonal Decomposition (POD) with deep learning residual error correction. Deep learning is used for error correction in both the projection and time integration phases of the ROM. This enables simultaneous correction within the POD subspace (error in the reduced subspace) and outside (truncation error). The present hybrid ROM is trained using an end-to-end neural Ordinary Differential Equations (ODE) framework, aligning the deep learning component with the continuous-time nature of the governing equations. We evaluate its performance using well-studied test cases: the viscous Burgers equation, the cylinder flow at a single Reynolds number (equal to 100), as well as for Reynolds numbers ranging from 60 to 120 (parametric cylinder case) and the fluidic pinball in the quasi-periodic regime. These non-chaotic test cases, are chosen to assess different aspects of the method and its ability to accurately predict reproducible dynamics. Our novel strategy outperforms several existing approaches both in terms of accuracy and dimensionality reduction: POD Galerkin ROMs, a purely data-driven approach using only autoencoders, and also state-of-the-art hybrid methods. Furthermore, it offers low computational overhead compared to classical POD-based ROMs, making it attractive for complex 2D or 3D systems.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"302 ","pages":"Article 106811"},"PeriodicalIF":3.0,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107142","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

Unconditionally local bounds preserving numerical scheme based on inverse Lax–Wendroff procedure for advection on networks 基于逆Lax-Wendroff过程的网络平流无条件局部保界数值格式

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-08-29 DOI: 10.1016/j.compfluid.2025.106806

Peter Frolkovič , Svetlana Krišková , Katarína Lacková

{"title":"Unconditionally local bounds preserving numerical scheme based on inverse Lax–Wendroff procedure for advection on networks","authors":"Peter Frolkovič , Svetlana Krišková , Katarína Lacková","doi":"10.1016/j.compfluid.2025.106806","DOIUrl":"10.1016/j.compfluid.2025.106806","url":null,"abstract":"<div><div>We derive an implicit numerical scheme for the solution of advection equation where the roles of space and time variables are exchanged using the inverse Lax–Wendroff procedure. The scheme contains a linear weight for which it is always second-order accurate in time and space, and the stencil in the implicit part is fully upwinded for any value of the weight, enabling a direct computation of numerical solutions by forward substitution. To fulfill the local bounds for the solution represented by the discrete minimum and maximum principle (DMP), we use a predicted value obtained with the linear weight and check a priori if the DMP is valid. If not, we can use either a nonlinear weight or a limiter function that depends on Courant number and apply such a high-resolution version of the scheme to obtain a corrected value. The advantage of the scheme obtained with the inverse Lax–Wendroff procedure is that only in the case of too small Courant numbers, the limiting is towards the first-order accurate scheme, which is not a situation occurring in numerical simulations with implicit schemes very often. In summary, the local bounds are satisfied up to rounding errors unconditionally for any Courant numbers, and the formulas for the predictor and the corrector are explicit. The high-resolution scheme can be extended straightforwardly for advection with a nonlinear retardation coefficient with numerical solutions satisfying the DMP, and a scalar nonlinear algebraic equation has to be solved to obtain each predicted and corrected value. In numerical experiments, including transport on a sewer network, we can confirm the advantageous properties of numerical solutions for several representative examples.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"301 ","pages":"Article 106806"},"PeriodicalIF":3.0,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144922910","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

An adjoint method for optimal linear perturbations of inviscid compressible flows with moving boundaries 带移动边界的无粘可压缩流的最优线性扰动的伴随方法

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-08-28 DOI: 10.1016/j.compfluid.2025.106799

Jean-Gabriel Thiriet , Grégoire Varillon , Jean-Marie Clarisse , Arnaud Couairon

{"title":"An adjoint method for optimal linear perturbations of inviscid compressible flows with moving boundaries","authors":"Jean-Gabriel Thiriet , Grégoire Varillon , Jean-Marie Clarisse , Arnaud Couairon","doi":"10.1016/j.compfluid.2025.106799","DOIUrl":"10.1016/j.compfluid.2025.106799","url":null,"abstract":"<div><div>Hydrodynamic instabilities play a critical role in the dynamics of inertial confinement fusion (ICF) and other compressible flows involving moving boundaries and shock waves. This paper presents a continuous adjoint-based optimization framework for identifying optimal linear perturbations in compressible inviscid flows with moving boundaries, with applications to ICF-relevant configurations. The method systematically derives adjoint equations using Lagrange multipliers and the duality principle, enabling the computation of optimal initial and external perturbations. Two case studies are treated: the homogeneous compression of a spherical shell and the propagation of a rarefaction wave. The study of imploding shells identifies perturbation transient growth as a result of sound wave amplification at large wavelengths. A receptivity analysis of rarefaction flows evidences the importance of multi-frequency effects as well as an increased amplification of small wavelength perturbations. The findings emphasize the efficacy, robustness, and computational efficiency of the method while providing new insights into the stability of dynamic flows in ICF. This work constitutes a significant step towards extending nonmodal linear stability analysis to complex compressible unsteady flows with moving boundaries and fronts and underscores the importance of considering transient perturbation dynamics in assessing the performance of ICF implosions.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"302 ","pages":"Article 106799"},"PeriodicalIF":3.0,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005092","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

A TVD-MRWENO limiter applied in the discontinuous Galerkin method for hyperbolic conservation laws 一种TVD-MRWENO限制器应用于双曲型守恒律的不连续Galerkin方法

IF 3 3区工程技术

Computers & Fluids Pub Date : 2025-08-26 DOI: 10.1016/j.compfluid.2025.106809

Yi Zhong , Pengcheng Du , Fangfei Ning

{"title":"A TVD-MRWENO limiter applied in the discontinuous Galerkin method for hyperbolic conservation laws","authors":"Yi Zhong , Pengcheng Du , Fangfei Ning","doi":"10.1016/j.compfluid.2025.106809","DOIUrl":"10.1016/j.compfluid.2025.106809","url":null,"abstract":"<div><div>The discontinuous Galerkin (DG) method is a widely used high-order numerical technique in Computational Fluid Dynamics (CFD). However, dealing with strong discontinuities within the framework of the DG method is still an important and open question. Recently, an attractive and promising limiter known as multi-resolution weighted essentially non-oscillatory (MRWENO) was proposed. It has the potential for widespread application due to its compactness, simplicity, and effectiveness for arbitrary orders. Nevertheless, it suffers from the drawback of generating excessive spurious oscillations and lacking sufficient robustness. This paper presents an improved limiter, TVD-MRWENO, which provides enhanced efficiency and robustness. The over-identification of troubled cells is avoided, and spurious oscillations in the post-shock region are also decreased. The procedure of the TVD-MRWENO limiter involves identifying troubled cells, applying first-order Total Variation Diminishing (TVD) limitations, and implementing high-order multi-resolution WENO reconstruction. For the first-order approximated DG method (denoted as P<sup>1</sup>), the TVD-MRWENO limiter reduces to the classic TVD-minmod limiter with a troubled cell indicator. For higher-order DG methods, multi-resolution WENO reconstruction is employed based on the first-order TVD-limited results to preserve the essentially non-oscillatory property and high resolution. A number of test cases are presented to demonstrate the improved accuracy, efficiency, and robustness of the TVD-MRWENO limiter compared to the MRWENO limiter.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"301 ","pages":"Article 106809"},"PeriodicalIF":3.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920408","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