Computers & Fluids最新文献

{"title":"A data-driven actuator-line methodology for the simulation of high-lift aircraft wake systems","authors":"S. Bennie ,&nbsp;P. Nagy ,&nbsp;M. Fossati","doi":"10.1016/j.compfluid.2025.106578","DOIUrl":"10.1016/j.compfluid.2025.106578","url":null,"abstract":"<div><div>The actuator-line method is here integrated with a data-driven approach for the investigation of aircraft-induced trailing vortices as generated by landing and take-off configurations with varying levels of high-lift device deflections. It is shown that through coupling the Actuator-Line-Method to a suitable Reduced-Order-Model built upon spanwise aerodynamic force distributions obtained from high-fidelity CFD solution data. The resulting wake from the geometry can be reproduced in a manner that no longer requires an explicit representation of the aircraft geometry within the simulation environment. The result is a method that allows for increased fidelity in the vortex farfield when studying the relevant wake dynamics and evolution during take-off, climb, approach and landing. The accuracy of the proposed method is assessed via a direct comparison to traditional high-fidelity nearfield derived results where it was observed that the induced downstream velocity profile and resulting location of vortex structures displayed a satisfactory level of agreement. With the creation of such a method, the effects of variations in aircraft high-lift deployment can be included within the simulation of downstream vortex pairs in a manner that respects the computational limitations of current hardware.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106578"},"PeriodicalIF":2.5,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Topology optimization for particle flow problems using Eulerian-Eulerian model with a finite difference method","authors":"Chih-Hsiang Chen,&nbsp;Kentaro Yaji","doi":"10.1016/j.compfluid.2025.106573","DOIUrl":"10.1016/j.compfluid.2025.106573","url":null,"abstract":"<div><div>Particle flow processing is widely employed across various industrial applications and technologies. Due to the complex interactions between particles and fluids, designing effective devices for particle flow processing is challenging. In this study, we propose a topology optimization method to design flow fields that effectively enhance the resistance encountered by particles. Particle flow is simulated using an Eulerian–Eulerian model based on a finite difference method. Automatic differentiation is implemented to compute sensitivities using a checkpointing algorithm. We formulate the optimization problem as maximizing the variation of drag force on particles while reducing fluid power dissipation. Initially, we validate the finite difference flow solver through numerical examples of particle flow problems and confirm that the corresponding topology optimization produces a result comparable to the benchmark problem. In the optimization cases, we explore both symmetric and asymmetric flow scenarios. For the symmetric flow case, the optimized flow fields indicate that serpentine flow fields can enhance particle drag variation while accounting for power dissipation. Furthermore, we investigate the effects of Reynolds numbers (<span><math><mrow><mi>R</mi><mi>e</mi><mo>≤</mo><mn>100</mn></mrow></math></span>) and Stokes numbers (<span><math><mrow><mi>St</mi><mo>&lt;</mo><mn>1</mn></mrow></math></span>) on the optimized flow field. The results demonstrate that increasing the Reynolds number results in more bends and greater curvature in the flow field, whereas increasing the Stokes number reduces these features. For the asymmetric flow case, gravity influences particle distribution, leading the serpentine flow paths to adjust their overall orientation to align with these regions of higher particle concentration.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106573"},"PeriodicalIF":2.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multirate time stepping for aeroelastic simulations of wind turbines using the actuator line model","authors":"Konstantina Ntrelia ,&nbsp;Stefan Vandewalle ,&nbsp;Johan Meyers","doi":"10.1016/j.compfluid.2025.106574","DOIUrl":"10.1016/j.compfluid.2025.106574","url":null,"abstract":"<div><div>In this study we introduce a novel high-order tight coupling methodology based on multirate generalized additive Runge–Kutta schemes, for the aeroelastic simulations of wind turbines. A large eddy simulation framework is coupled to a multibody structural model by utilizing the multirate technique. Turbines are represented by the actuator line model. We explore two different scenarios depending on component partitioning and test them in terms of accuracy and performance. The two coupling approaches are tested in simulations of an NREL 5 MW reference wind turbine inside a uniform inflow. The scheme preserves a high-order accuracy for both coupling methods, while we observe a strong dependency of the numerical solution on the partitioning and the multirate ratio. The implemented multirate schemes demonstrate great potential for achieving algorithmic speed-ups for aeroelastic simulations compared to single-rate methods.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106574"},"PeriodicalIF":2.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465381","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}

{"title":"A hybrid diffuse boundary approach for modeling contact-line dynamics within the framework of phase-field lattice Boltzmann method","authors":"Guanlong Guo ,&nbsp;Beichen Ji ,&nbsp;Pei Zhang ,&nbsp;Bin Chen ,&nbsp;S.A. Galindo-Torres","doi":"10.1016/j.compfluid.2025.106575","DOIUrl":"10.1016/j.compfluid.2025.106575","url":null,"abstract":"<div><div>Modeling the dynamics of the contact line among liquid, gas, and solid phases requires enforcing three fundamental boundary conditions on the solid surface: non-penetration, no-slip, and wetting. This study presents a hybrid diffuse boundary approach within the phase-field lattice Boltzmann method to effectively model contact-line dynamics. The proposed method integrates the diffuse domain approach into the Cahn-Hilliard equation to impose the wetting boundary condition, while the smoothed profile method is incorporated into the Navier–Stokes equation to enforce the no-slip and non-penetration conditions. By leveraging the diffuse nature of the boundary/interface, this approach naturally embeds all three boundary conditions directly into the governing equations, eliminating the need for complex numerical treatments at solid boundaries. Compared to the conventional sharp boundary method and the immersed boundary method, the hybrid approach significantly simplifies boundary condition implementation, particularly for complex geometries and moving solid boundaries. Validation tests confirm the accuracy of the method in reproducing prescribed contact angles and ensuring mass conservation. Furthermore, the approach is applied to simulate bubble migration through a pore throat, demonstrating a linear relationship between the Bond number and the contact angle, which delineates distinct passing and trapping behaviors.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106575"},"PeriodicalIF":2.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479051","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}

{"title":"A hybrid immersed-boundary/front-tracking method for interface-resolved simulation of droplet evaporation","authors":"Faraz Salimnezhad ,&nbsp;Hasret Turkeri ,&nbsp;Iskender Gokalp ,&nbsp;Metin Muradoglu","doi":"10.1016/j.compfluid.2025.106570","DOIUrl":"10.1016/j.compfluid.2025.106570","url":null,"abstract":"<div><div>A hybrid sharp-interface immersed-boundary/front-tracking (IB/FT) method is developed for interface-resolved simulation of evaporating droplets in incompressible multiphase flows. A one-field formulation is used to solve the flow, species mass fraction and energy equations in the entire computational domain with appropriate jump conditions at the interface. An image point and ghost cell methodology is coupled with a front-tracking method to achieve an overall second order spatial accuracy for the mass fraction boundary condition on the droplet surface. The immersed-boundary method is also extended to simulate mass transfer from a solid sphere in a convective environment. The numerical method is first validated for the standard benchmark cases and the results are found to be in good agreement with analytical solutions. The method is shown to be overall second order accurate in space. Employing a moving reference frame methodology, the method is then applied to simulate evaporation of a deformable droplet in a convective environment and the results are compared with the existing evaporation models widely used in spray combustion simulations.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106570"},"PeriodicalIF":2.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421507","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}

{"title":"Modeling of interfacial two-phase flows via VOF-based LS method with WENO scheme in the finite volume method","authors":"Wenkang Meng ,&nbsp;Ching-hao Yu ,&nbsp;Jia Li ,&nbsp;Zhiyuan Wu ,&nbsp;Ruidong An","doi":"10.1016/j.compfluid.2025.106580","DOIUrl":"10.1016/j.compfluid.2025.106580","url":null,"abstract":"<div><div>The modeling of interfacial two-phase flows involves various fields such as hydraulic engineering, marine engineering, chemical industry, etc., whose difficulty lies in the accurate simulation of the two-phase flow interface. This paper presents a VOF(volume of fluid)-based LS (level set) method with WENO (weighted essentially non-oscillatory) scheme in the finite volume method. The proposed method initializes the LS function by transforming the VOF function, which does not have the characteristics of the distance function yet. Therefore, the next step is to re-distance the transformed LS function by solving the re-initialization equation. For solving the re-initialization equation, the WENO scheme in the finite volume method is employed, providing fifth-order accuracy for the convection term. To validate the proposed VOF-based LS method combined with the WENO scheme, five test cases are presented, including Zalesak's disk, vortex deformation, Rayleigh-Taylor instability, two-dimensional bubble rise, and dam break flow. The numerical results from these interfacial two-phase flow cases demonstrate that the VOF-based LS method with the WENO scheme in the finite volume method can achieve accurate capture of the interface while maintaining excellent mass conservation characteristics.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106580"},"PeriodicalIF":2.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453553","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}

{"title":"A reconstruction technique for high-order variational finite volume schemes based on conjugate gradient method","authors":"Fangkun Ni ,&nbsp;Jianhua Pan ,&nbsp;Wei-Gang Zeng ,&nbsp;Yu-Xin Ren","doi":"10.1016/j.compfluid.2025.106576","DOIUrl":"10.1016/j.compfluid.2025.106576","url":null,"abstract":"<div><div>This paper proposes a novel reconstruction technique based on conjugate gradient method for the variational finite volume schemes. Compared with the Gauss-Seidel or Jacobi iteration based variational finite volume schemes, the conjugate gradient method based variational finite volume schemes not only have a superior convergence rate but also are cell-wise parallel and suit for computational devices like graphic processing units. Benchmark cases including 2-D and 3-D, steady and unsteady, inviscid and viscous cases demonstrate the effectiveness and high efficiency of the proposed technique.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106576"},"PeriodicalIF":2.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444340","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}

{"title":"Non-dimensional meshing criterion of mean flow field discretization for RANS and LES","authors":"H. Lam,&nbsp;T. Berthelon,&nbsp;G. Balarac","doi":"10.1016/j.compfluid.2025.106572","DOIUrl":"10.1016/j.compfluid.2025.106572","url":null,"abstract":"<div><div>When turbulent flows occur, Reynolds Average Navier–Stokes (RANS) and Large-Eddy Simulation (LES) approaches are now valuable strategies to numerically study complex systems. An open question is still to be able to define an adequate mesh, i.e. guaranteeing accuracy of the numerical simulations but limiting the number of mesh elements to limit computational cost. RANS and LES approaches differ in term of level of description of the turbulent fields, but these approaches share the same objective to obtain mean fields independent of the mesh. Based on the Reynolds equation, a new mesh size based Reynolds number, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>Δ</mi></mrow></msub></mrow></math></span>, is derived. This new criterion is the upper bound of a non-dimensional error estimation of the mean velocity field. This new criterion can also be interpreted by analogy with the Kolmogorov scale, <span><math><mi>η</mi></math></span>. Indeed, <span><math><mi>η</mi></math></span> can be interpreted as the scale where the instantaneous dynamic is dominated by (molecular) diffusive effects, leading to the Kolmogorov Reynolds number, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>η</mi></mrow></msub><mo>∼</mo><mn>1</mn></mrow></math></span>. Similarly, <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>Δ</mi></mrow></msub></mrow></math></span> will be close to 1 at scale <span><math><mi>Δ</mi></math></span> where molecular and turbulent diffusive effects dominate the mean field dynamic. This allows to define the local mesh size to guarantee a correct discretization of the mean field. This criterion is applied in various flow configuration for LES, with and without law of the wall, as well as RANS simulations with great accuracy. In practice, it is found that the value <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>Δ</mi></mrow></msub><mo>∼</mo><mn>1</mn></mrow></math></span> appears indeed as a good compromise in terms of number of elements and precision. This allows to easily obtain an adequate mesh for the mean flow velocity field, without a priori knowledge of the flow dynamic.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"291 ","pages":"Article 106572"},"PeriodicalIF":2.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430278","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}

{"title":"Mitigation of Shock wave boundary layer interaction using surface arc plasma energy actuators: A computational study","authors":"Deepu Dinesan,&nbsp;Bibin John","doi":"10.1016/j.compfluid.2025.106569","DOIUrl":"10.1016/j.compfluid.2025.106569","url":null,"abstract":"<div><div>The control of shock wave boundary layer interaction (SWBLI) by means of surface arc plasma actuator (SAPA) is the focus of current work. The primary objective is to explore the potential of short-duration pulse energy deposition in mitigating the separation zone that develops ahead of a cylindrical blunt body placed in a supersonic Mach 2.5 field. The research delves into the fundamental physics of BW generation and propagation, both in quasi-static fields and supersonic flows. Additionally, it elucidates how BWs interact with the separated shear layer, ultimately reducing the size of the separation zone. The numerical framework implemented for the replication of real time surface arc plasma energy addition is validated against the literature reported experimental and analytical data. Additional parametric studies demonstrating the effect of plasma actuation duration, energy magnitude/pulse and number of SAPAs are presented. Notably, the findings reveal that an array of SAPAs with five energy pulse locations can minimize the separation size to just 56% of the base flow, with one time actuation of SAPAs by depositing <span><math><mrow><mn>240</mn><mi>m</mi><mi>J</mi></mrow></math></span> of energy.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"290 ","pages":"Article 106569"},"PeriodicalIF":2.5,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395075","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}

{"title":"Goal-oriented adaptive sampling for projection-based reduced-order models","authors":"Donovan Blais,&nbsp;Siva Nadarajah,&nbsp;Calista Biondic","doi":"10.1016/j.compfluid.2025.106568","DOIUrl":"10.1016/j.compfluid.2025.106568","url":null,"abstract":"<div><div>Modern aircraft design involves a large number of design parameters from a multitude of disciplines. Obtaining high-fidelity solutions for all combinations of such parameters is computationally unfeasible. Although the solution to a large-scale system of equations is generally an element of a large-dimensional space, the solution may actually lie on a reduced-order subspace induced by parameter variation. In order to capture this subspace, samples of the high-dimensional system called snapshots are used to build a reduced-order model. These models have generated interest as a means to compute high-fidelity solutions at a much lower computational cost. However, little value can be placed in a reduced-order solution without some quantification of its error. The dual-weighted residual can be used to obtain error estimates between the outputs of different models. Using dual-weighted residual error estimates in conjunction with a radial basis function interpolation, this work introduces a novel adaptive sampling method that chooses snapshots iteratively such that a prescribed output error tolerance is estimated to be met on the entirety of a parameter space. The adaptive sampling procedure is demonstrated on a one-dimensional Burgers’ equation and two-dimensional inviscid flows.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"290 ","pages":"Article 106568"},"PeriodicalIF":2.5,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}