Computers & Fluids最新文献_第10页

Optimized workload distribution for GPU-accelerated combustion simulations in heterogeneous CPU–GPU architectures 异构CPU-GPU架构中gpu加速燃烧模拟的优化工作负载分配

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-24 DOI: 10.1016/j.compfluid.2025.106846

Álvaro Moure, Anurag Surapaneni, Daniel Mira

This work presents a set of workload distribution algorithms designed to optimize the hybrid use of CPUs and GPUs in reacting flow simulations on heterogeneous High-Performance Computing (HPC) systems. The algorithms extend advanced computational software originally developed for CPUs to hybrid CPU–GPU environments. Unlike GPU-exclusive software, hybrid codes require specialized orchestration to maximize GPU utilization while minimizing CPU idle time. Combustion simulations are computationally demanding due to the evaluation of non-linear source terms and the transport of large number of PDEs with strong imbalanced MPI workloads, so it requires highly efficient codes with advanced parallel algorithms. Algorithms based on different MPI-GPU mapping roles defined to maximize chemistry batch size while reducing GPU communication overhead are proposed to accelerate combustion simulations using heterogeneous HPC systems. These approaches offload the expensive chemical integration step to the GPUs, while the transport remains on the CPUs using an operator splitting technique. Stiff chemical integration is GPU-accelerated with ChemInt, a newly developed CPU/GPU-compatible C++/CUDA library designed for coupling with CPU-based CFD codes. A comparison of the different approaches is presented and discussed demonstrating performance improvements of more than threefold over CPU-only executions.

这项工作提出了一套工作负载分配算法，旨在优化cpu和gpu在异构高性能计算（HPC）系统反应流模拟中的混合使用。这些算法将最初为cpu开发的高级计算软件扩展到CPU-GPU混合环境。与GPU专用软件不同，混合代码需要专门的编排来最大化GPU利用率，同时最小化CPU空闲时间。由于燃烧模拟需要对非线性源项进行评估，并且需要传输大量具有强不平衡MPI负载的pde，因此需要具有先进并行算法的高效代码。提出了基于不同MPI-GPU映射角色的算法，以最大化化学批处理规模，同时减少GPU通信开销，从而加速异构HPC系统的燃烧模拟。这些方法将昂贵的化学集成步骤卸载到gpu上，而使用算子拆分技术将传输留在cpu上。ChemInt是一种新开发的CPU/ gpu兼容c++ /CUDA库，旨在与基于CPU的CFD代码耦合。本文给出并讨论了不同方法的比较，证明了与仅使用cpu执行相比，性能提高了三倍以上。

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引用次数: 0

Density-based topology optimization strategy for optimal design of uniform flow manifolds 基于密度的均匀流管优化设计拓扑优化策略

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-24 DOI: 10.1016/j.compfluid.2025.106847

Sanjay Vermani , Nitish Anand

Flow manifolds are devices that distribute or collect fluid across multiple channels, playing a crucial role in the performance of many fluid and energy systems. However, designing efficient manifolds that ensure uniform flow distribution remains challenging, especially for multi-channel three-dimensional manifolds. This study presents a scalable topology optimization framework for systematically designing multi-channel flow manifolds. The proposed method builds on the conventional density-based topology optimization formulation by introducing a flow maldistribution coefficient as an explicit constraint. This novel approach was implemented using the incompressible Navier–Stokes flow solver available in the open-source CFD suite SU2. The performance of the proposed method was benchmarked against two established topology optimization strategies using an exemplary planar z-type flow manifold, where both the inlet and outlet manifolds were designed simultaneously. The results demonstrate that the proposed method achieves flow uniformity comparable to established approaches while significantly reducing computational costs. Furthermore, when applied to large-scale three-dimensional problems, the proposed method produces feasible designs that achieve uniform flow distribution and exhibit innovative geometrical features. These results highlight the robustness and scalability of the proposed method.

流动歧管是一种通过多个通道分配或收集流体的装置，在许多流体和能源系统的性能中起着至关重要的作用。然而，设计出能够保证均匀流动分布的高效歧管仍然具有挑战性，特别是对于多通道三维歧管。本研究提出了一个可扩展的拓扑优化框架，用于系统地设计多通道流形。该方法建立在传统的基于密度的拓扑优化公式的基础上，引入了流量不均匀系数作为显式约束。这种新颖的方法是使用开源CFD套件SU2中的不可压缩Navier-Stokes流求解器实现的。以一个同时设计进、出口流形的平面z型流形为例，对比两种已建立的拓扑优化策略，对所提方法的性能进行了基准测试。结果表明，该方法在显著降低计算成本的同时，获得了与现有方法相当的流动均匀性。此外，当应用于大规模的三维问题时，该方法产生了可行的设计，实现了均匀的流动分布，并表现出创新的几何特征。这些结果突出了该方法的鲁棒性和可扩展性。

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引用次数: 0

A 3D Eulerian meshless conservative level set method for two-phase flows with complex geometries 复杂几何两相流的三维欧拉无网格保守水平集方法

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-23 DOI: 10.1016/j.compfluid.2025.106839

Anand S. Bharadwaj , B. Premachandran

In this paper, we develop a 3D Eulerian meshless method based on the conservative level set method targeted to solve two-phase flows with complex geometries. The method combines the advantages of Eulerian methods and meshless methods. Being an Eulerian method, it does not require neighbourhood estimation every time step. At the same time, being a meshless method, it does not require mesh connectivity between points in the domain and consequently, alleviates the difficulty of mesh-generation, makes point cloud adaptation and simulation with complex geometries relatively straight forward. In this method, we use a point cloud generating algorithm as a part of the fluid-solver, which can be used to generate or change the point cloud whenever there are any geometric changes in the domain. The meshless method is based on the Generalized Finite Difference Method (GFDM), which uses differential operators that are derived from a least-squares error minimization procedure. The advection equation of the volume fraction

α

uses the Directional Flux Error Minimization (DFEM) scheme. The 5th order WENO scheme is used for the flux-reconstruction in the advection equation. The interface sharpening step is performed at regular intervals to ensure that the sharpness of the interface is retained, thus, reducing the mass losses associated with the dissipative errors in the advection step. To further improve the accuracy, we propose the adaptation of the point cloud in the vicinity of the interface using the convolution of the volume fraction function (

α

). The method is validated using benchmark test cases. Additionally, some flow problems involving complex geometries are presented — flow through a porous cavity with uniform and randomly distributed obstacles and the flow of molten metal in the casting of a helical bevel gear.

针对复杂几何形状的两相流问题，提出了一种基于保守水平集法的三维欧拉无网格方法。该方法结合了欧拉法和无网格法的优点。作为一种欧拉方法，它不需要在每个时间步都进行邻域估计。同时，作为一种无网格方法，它不需要域内点之间的网格连通性，从而减轻了网格生成的难度，使得具有复杂几何形状的点云适应和模拟相对简单。在该方法中，我们将点云生成算法作为流体求解器的一部分，该算法可用于在域中发生任何几何变化时生成或更改点云。无网格方法基于广义有限差分法（GFDM），该方法使用由最小二乘误差最小化过程导出的微分算子。体积分数α的平流方程采用定向通量误差最小化（DFEM）格式。采用5阶WENO格式对平流方程进行通量重建。界面锐化步骤按一定的间隔进行，以确保界面的锐化保持不变，从而减少与平流步骤中耗散误差相关的质量损失。为了进一步提高精度，我们提出使用体积分数函数（α）的卷积来适应界面附近的点云。使用基准测试用例验证了该方法。此外，还讨论了一些复杂几何形状的流动问题，如具有均匀和随机分布障碍物的多孔腔的流动问题以及斜齿锥齿轮铸造过程中熔融金属的流动问题。

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引用次数: 0

Phase-field modeling of melting processes in viscoelastic materials 粘弹性材料熔化过程的相场模拟

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-23 DOI: 10.1016/j.compfluid.2025.106845

Hongfei Xie, Ying Meng, Kang Luo, Hongliang Yi

In this paper, the solid–liquid phase change problems of viscoelastic materials are solved using the spectral element method (SEM). The phase-field method is employed to simulate the melting dynamics, while the log-conformation reformulation (LCR) method is utilized to address the high Weissenberg number problem (HWNP). The reliability of the proposed numerical model is systematically validated through benchmark comparisons with literature data and finite volume method (FVM) simulations. Subsequently, a comprehensive analysis is conducted to investigate the influence of viscoelastic effects on the melting dynamics in a cavity under different Rayleigh and Weissenberg numbers. The computational results demonstrate that the viscoelastic effect significantly enhances heat transfer efficiency and accelerates the melting process. This enhancement can be attributed to the viscoelastic effects that effectively reduce flow resistance while enhancing the average kinetic energy of convective flows.

本文采用谱元法（SEM）求解粘弹性材料的固液相变问题。采用相场法模拟熔融动力学，采用对数构象重构法求解高魏森伯格数问题。通过与文献数据和有限体积法（FVM）模拟的基准比较，系统地验证了所提出的数值模型的可靠性。随后，综合分析了不同瑞利数和魏森伯格数下粘弹性效应对腔内熔化动力学的影响。计算结果表明，粘弹性效应显著提高了传热效率，加速了熔化过程。这种增强可以归因于粘弹性效应，它有效地降低了流动阻力，同时提高了对流流动的平均动能。

引用次数: 0

On the applicability of the EDAC method to non-Oberbeck–Boussinesq regimes in buoyancy-driven flows 关于EDAC方法在浮力驱动流中非oberbeck - boussinesq格式中的适用性

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-22 DOI: 10.1016/j.compfluid.2025.106835

Kasturi Srikanth , V. Praveen Kumar , T. Jayachandran , A. Sameen , Manjul Sharma

This work presents an extension of the Entropically Damped Artificial Compressibility (EDAC) method to simulate buoyancy-driven flows under Non-Oberbeck–Boussinesq (NOB) conditions, characterized by strong thermophysical property variations. By integrating realistic data from the National Institute of Standards and Technology (NIST) database, the formulation accounts for temperature-dependent density and transport coefficients. A sixth-order compact finite-difference scheme with high-order filtering and Runge–Kutta time integration is used to solve the equations in a Rayleigh–Benard convection configuration for air, water, and steam. Diagnostic quantities such as the central temperature shift, relative Nusselt number, and RMS velocity divergence confirm agreement with existing literature. Despite not enforcing incompressibility explicitly, the method exhibits low divergence errors, even in high density gradient cases like steam. These results demonstrate the accuracy and robustness of EDAC for NOB flows, offering a viable alternative to traditional pressure Poisson solvers.

这项工作提出了熵阻尼人工压缩（EDAC）方法的扩展，以模拟非oberbeck - boussinesq （NOB）条件下的浮力驱动流动，其特征是强烈的热物理性质变化。通过整合美国国家标准与技术研究院（NIST）数据库中的实际数据，该公式考虑了温度相关的密度和输运系数。采用高阶滤波和龙格-库塔时间积分的六阶紧致有限差分格式求解了空气、水和蒸汽的瑞利-贝纳德对流方程。诊断量，如中心温度变化，相对努塞尔数和均方根速度散度证实与现有文献一致。尽管没有明确地强制不可压缩性，该方法显示出低发散误差，即使在高密度梯度的情况下，如蒸汽。这些结果证明了EDAC对NOB流体的准确性和鲁棒性，为传统压力泊松求解器提供了可行的替代方案。

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引用次数: 0

Disentangled latent spaces for reduced order models using deterministic autoencoders 使用确定性自编码器的降阶模型的解纠缠潜在空间

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-19 DOI: 10.1016/j.compfluid.2025.106837

Henning Schwarz , Pyei Phyo Lin , Jens-Peter M. Zemke , Thomas Rung

Data-driven reduced-order models based on autoencoders generally lack interpretability compared to classical methods such as the proper orthogonal decomposition. More interpretability can be gained by disentangling the latent variables and analyzing the resulting modes. For this purpose, probabilistic

β

-variational autoencoders (

β

-VAEs) are frequently used in computational fluid dynamics and other simulation sciences. Using a benchmark periodic flow dataset, we show that competitive results can be achieved using non-probabilistic autoencoder approaches that either promote orthogonality or penalize correlation between latent variables. Compared to probabilistic autoencoders, these approaches offer more robustness with respect to the choice of hyperparameters entering the loss function. We further demonstrate the ability of a non-probabilistic approach to identify a reduced number of active latent variables by introducing a correlation penalty, a function also known from the use of

β

-VAE. The investigated probabilistic and non-probabilistic autoencoder models are finally used for the dimensionality reduction of aircraft ditching loads, which serves as an industrial application in this work.

与传统的正交分解方法相比，基于自编码器的数据驱动降阶模型通常缺乏可解释性。通过解开潜在变量并分析产生的模式，可以获得更多的可解释性。为此，概率β-变分自编码器（β-VAEs）经常用于计算流体动力学和其他模拟科学。使用基准周期流数据集，我们表明使用非概率自编码器方法可以实现竞争结果，该方法可以促进潜在变量之间的正交性或惩罚相关性。与概率自编码器相比，这些方法在选择进入损失函数的超参数方面提供了更强的鲁棒性。我们进一步证明了非概率方法通过引入相关惩罚来识别减少数量的活动潜在变量的能力，该函数也可以从β-VAE的使用中得知。最后将所研究的概率和非概率自编码器模型用于飞机迫降载荷的降维，并在本工作中具有工业应用价值。

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引用次数: 0

Immersed boundaries in the discontinuous Galerkin spectral element method through hp-adaptivity 基于hp自适应的不连续伽辽金谱元方法中浸入边界

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-19 DOI: 10.1016/j.compfluid.2025.106840

Amit Nayak, Catherine Mavriplis

The immersed boundary method is a promising numerical technique that allows for modeling of complex geometries without the need for body conforming meshes. However, immersed boundary methods present a significant reduction in accuracy. In this paper, we implement the volume penalty method in an hp-adaptive discontinuous Galerkin spectral method framework to solve the two-dimensional acoustic wave equation with immersed boundaries. We demonstrate that combining low porosity, which represents the immersed boundary, with hp-adaptivity reduces oscillations, localizes error to the vicinity of the immersed boundary and improves the overall accuracy. A variety of test cases are presented to show that the implementation is capable of modeling wave propagation in complex geometries with simple Cartesian grids.

浸没边界法是一种很有前途的数值模拟技术，它可以模拟复杂的几何形状，而不需要体的一致性网格。然而，浸入边界法的精度明显降低。本文在自适应间断伽辽金谱法框架下，采用体积惩罚法求解具有浸入边界的二维声波方程。研究表明，将低孔隙度（即浸入边界）与高频自适应相结合可以减少振荡，将误差定位在浸入边界附近，从而提高整体精度。给出了各种测试用例，表明该实现能够用简单的笛卡尔网格模拟复杂几何形状中的波传播。

引用次数: 0

An efficient computational method for studying the interaction of strong turbulence with a free-surface 研究强湍流与自由表面相互作用的有效计算方法

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-19 DOI: 10.1016/j.compfluid.2025.106836

Andre Calado, Ibrahim Yildiran, Elias Balaras

Strong turbulence interacting with a free-surface is a challenging problem, where the interface between gas and liquid is disrupted, generating droplets and bubbles. Turbulent bubble entrainment and breakdown is of paramount importance to quantify mass and momentum transport, and developing lower order models. Thus far, computational costs of scale resolving simulations (for both interface and turbulence) have limited the ability to study these flows. In this work we leverage recent advances in two-phase solvers, including a splitting scheme for the Poisson equation allowing the use of FFT-based Fast Poisson Solvers (FPS) greatly reducing solution time, with verifiable accuracy; coupled with the Ghost Fluid Method (GFM) for a sharp interface treatment. The proposed formulation uses the level set approach, with a dual-redistancing scheme for global mass conservation of each phase. To analyze strong free-surface turbulence, homogeneous isotropic turbulence (HIT) is forced under an air–water interface to analyze stationary statistics of the flow including entrained bubble sizes and Reynolds stresses. Two different approaches are used for the sub-surface forcing. The first uses the common linear forcing scheme in physical space, which imposes a constraint on the domain size. The alternative approach relies on the synthetic random Fourier method to generate a boundary condition which reduces the total computational domain, allowing for higher Reynolds number simulations of turbulent free-surface flows.

与自由表面相互作用的强湍流是一个具有挑战性的问题，其中气体和液体之间的界面被破坏，产生液滴和气泡。湍流气泡的携带和破裂对于质量和动量输运的量化以及低阶模型的建立至关重要。到目前为止，尺度解析模拟（界面和湍流）的计算成本限制了研究这些流动的能力。在这项工作中，我们利用了两相求解器的最新进展，包括泊松方程的分裂方案，允许使用基于fft的快速泊松求解器（FPS），大大减少了求解时间，具有可验证的准确性；结合幽灵流体法（GFM）进行尖锐的界面处理。所提出的公式采用水平集方法，采用双重距离方案对每个相的全局质量守恒进行求解。为了分析强自由表面湍流，在空气-水界面下强迫均匀各向同性湍流（HIT）来分析包括夹带气泡大小和雷诺应力在内的流动静态统计。地下强迫有两种不同的方法。第一种方法在物理空间中使用常见的线性强迫方案，这对域的大小施加了约束。另一种方法依赖于合成随机傅立叶方法来生成边界条件，该边界条件减少了总计算域，从而允许湍流自由表面流动的高雷诺数模拟。

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引用次数: 0

Sparse Identification for bifurcating phenomena in Computational Fluid Dynamics 计算流体力学中分岔现象的稀疏识别

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-19 DOI: 10.1016/j.compfluid.2025.106841

Lorenzo Tomada, Moaad Khamlich, Federico Pichi, Gianluigi Rozza

This work investigates model reduction techniques for nonlinear parameterized and time-dependent PDEs, specifically focusing on bifurcating phenomena in Computational Fluid Dynamics (CFD). We develop interpretable and non-intrusive Reduced Order Models (ROMs) capable of capturing dynamics associated with bifurcations by identifying a minimal set of coordinates.

Our methodology combines the Sparse Identification of Nonlinear Dynamics (SINDy) method with a deep learning framework based on Autoencoder (AE) architectures. To enhance dimensionality reduction, we integrate a nested Proper Orthogonal Decomposition (POD) with the SINDy-AE architecture, enabling a sparse discovery of system dynamics while maintaining efficiency of the reduced model.

We demonstrate our approach via two challenging test cases defined on sudden-expansion channel geometries: a symmetry-breaking bifurcation and a Hopf bifurcation. Starting from a comprehensive analysis of their high-fidelity behavior, i.e. symmetry-breaking phenomena and the rise of unsteady periodic solutions, we validate the accuracy and computational efficiency of our ROMs.

The results show successful reconstruction of the bifurcations, accurate prediction of system evolution for unseen parameter values, and significant speed-up compared to full-order methods.

本文研究了非线性参数化和时变偏微分方程的模型简化技术，特别关注计算流体动力学（CFD）中的分岔现象。我们开发了可解释和非侵入性的降阶模型（rom），能够通过识别最小坐标集来捕获与分岔相关的动态。我们的方法结合了非线性动力学的稀疏识别（SINDy）方法和基于自编码器（AE）架构的深度学习框架。为了增强降维，我们将嵌套的适当正交分解（POD）与SINDy-AE体系结构相结合，在保持降维模型效率的同时，实现了系统动力学的稀疏发现。我们通过定义在突然扩展通道几何上的两个具有挑战性的测试用例来演示我们的方法：对称破坏分岔和Hopf分岔。从全面分析它们的高保真行为，即对称性破坏现象和非定常周期解的兴起开始，我们验证了我们的rom的准确性和计算效率。结果表明，与全阶方法相比，该方法可以成功地重建分岔，准确地预测未知参数值下的系统演化，并且具有显著的加速效果。

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引用次数: 0

ONERA’s CRM WBPN database for machine learning activities, related regression challenge and first results ONERA的CRM WBPN数据库，用于机器学习活动、相关回归挑战和首次结果

IF 3 3区工程技术 Q3 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers & Fluids

Pub Date : 2025-09-19 DOI: 10.1016/j.compfluid.2025.106838

Jacques Peter , Quentin Bennehard , Sébastien Heib , Jean-Luc Hantrais-Gervois , Frédéric Moëns

This paper presents a new Computational Fluid Dynamics database, developed at ONERA, to support the advancement of machine learning techniques for aerodynamic field prediction. It contains 468 Reynolds-Averaged Navier–Stokes simulations using the Spalart–Allmaras turbulence model, performed on the NASA/Boeing Common Research Model wing-body-pylon-nacelle configuration. The database spans a wide range of flow conditions, varying Mach number (including transonic regimes), angle of attack (capturing flow separation), and Reynolds number (based on three stagnation pressures, with one setting matching wind tunnel experiments). The numerical quality of the database is assessed, through checking the convergence level of each computation.

Based on these data, a regression challenge is defined. It consists in predicting the wall distributions of pressure and friction coefficients for unseen aerodynamic conditions. The 468 simulations are split into training and test sets, with the training data made available publicly on the Codabench platform. The paper further evaluates several classical machine learning regressors on this task. Tested pointwise methods include Multilayer Perceptrons,

λ

-DNNs, and Decision Trees, while global methods include Multilayer Perceptron, k-Nearest Neighbors, Proper Orthogonal Decomposition and IsoMap. Initial performance results, using

R^{2}

scores and largest relative mean absolute error metrics, are presented, offering insights into the capabilities of these techniques for the challenge and references for future work.

本文提出了一个新的计算流体动力学数据库，由ONERA开发，以支持空气动力场预测的机器学习技术的进步。它包含468个reynolds - average Navier-Stokes模拟，使用Spalart-Allmaras湍流模型，在NASA/波音通用研究模型翼-体-挂架-机舱配置上进行。该数据库涵盖了广泛的流动条件，不同的马赫数（包括跨音速状态），攻角（捕获流动分离）和雷诺数（基于三种停滞压力，其中一种设置与风洞实验相匹配）。通过检查每个计算的收敛程度来评估数据库的数值质量。基于这些数据，定义了回归挑战。它包括在未知气动条件下预测压力和摩擦系数的壁面分布。468个模拟被分为训练集和测试集，训练数据在codabbench平台上公开提供。本文进一步评估了几种经典的机器学习回归器。经过测试的点向方法包括多层感知机、λ- dnn和决策树，而全局方法包括多层感知机、k近邻、适当正交分解和IsoMap。给出了使用R2分数和最大相对平均绝对误差度量的初始性能结果，为这些技术的挑战和未来工作提供了参考。

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引用次数: 0