Computers & Fluids最新文献_第2页

Flow instability in a rotating channel loaded with an anisotropic porous material 加载各向异性多孔材料的旋转通道中的流动不稳定性

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-05 DOI: 10.1016/j.compfluid.2025.106689

Mrityunjoy Saha , Saunak Sengupta , Sudipto Mukhopadhyay , Sukhendu Ghosh

{"title":"Flow instability in a rotating channel loaded with an anisotropic porous material","authors":"Mrityunjoy Saha , Saunak Sengupta , Sudipto Mukhopadhyay , Sukhendu Ghosh","doi":"10.1016/j.compfluid.2025.106689","DOIUrl":"10.1016/j.compfluid.2025.106689","url":null,"abstract":"<div><div>The linear instability of flows within a channel that rotates spanwise and is filled with a non-uniform porous substance is investigated. The porous material is considered anisotropic in nature, with different permeabilities in the horizontal and vertical directions. The novel focus of this study is to explore the influence of the anisotropy property of porous media on the rotational instability of the flow. The flow is modeled using the extended Darcy-Brinkman equations, including a permeability matrix. The non-uniformity of the porous material is characterized by the parameter <span><math><mi>γ</mi></math></span>, defined as the ratio of horizontal permeability to vertical permeability. The flow problem is solved as an Orr–Sommerfeld-Squire type eigenvalue problem using normal mode assumptions and the Chebyshev collocation method. The temporal instabilities are computed and compared for two-dimensional (2D) spanwise disturbances and three-dimensional (3D) disturbances. Different unstable modes are found for both types of disturbances, and 2D spanwise perturbation waves provide dominant instability. The combined effects of the Coriolis force and the anisotropy of the porous layer on the temporal unstable modes are investigated using the marginal stability boundaries and growth rate curves. The critical rotation number for instability bifurcation is calculated over a physical interval of <span><math><mi>γ</mi></math></span>. It is observed that the reduction of the permeability ratio has a stabilizing effect. Further, the instability depends on a correlation between the porosity and rotational speed. Flow through a weakly porous medium exhibits linear instability at higher rotational speeds. The perturbation velocity distributions display roll cells near the lower wall for the unstable modes under anticlockwise system rotation. This phenomenon promotes secondary instability and micro-mixing inside the flow system.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106689"},"PeriodicalIF":2.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242440","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

Topology optimization of roughness elements to delay modal transition in boundary layers 粗糙度单元拓扑优化以延缓边界层的模态转变

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-03 DOI: 10.1016/j.compfluid.2025.106680

Harrison Nobis , Philipp Schlatter , Eddie Wadbro , Martin Berggren , Dan S. Henningson

{"title":"Topology optimization of roughness elements to delay modal transition in boundary layers","authors":"Harrison Nobis , Philipp Schlatter , Eddie Wadbro , Martin Berggren , Dan S. Henningson","doi":"10.1016/j.compfluid.2025.106680","DOIUrl":"10.1016/j.compfluid.2025.106680","url":null,"abstract":"<div><div>It is well understood that spanwise arrays of roughness elements can be used to generate steady streaks in boundary layers. This modulation of the boundary layer has the potential to attenuate the growth of Tollmien–Schlichting (TS) waves which can lead to the transition to turbulence in low turbulence intensity environments, such as those experienced by an aircraft’s fuselage in atmospheric flight. This article applies density based topology optimization in order to design roughness elements capable of exploiting the aforementioned stabilizing effect as a means of passive flow control. The geometry of the roughness elements are represented using a Brinkman penalization when conducting Direct Numerical Simulations (DNS) to simulate the streaky boundary layer flow. Similarly, the unsteady linearized Navier–Stokes equations are evolved to assess the spatial growth of the TS waves across the flat plate. The optimization procedure aims to minimize the TS wave amplitude at a given downstream position while a novel constraint is used promoting a stable baseflow. The optimization problem is solved with gradient descent algorithms where the adjoint-variable method is used to compute gradients. This method has been applied to three initial material distributions yielding three distinct and novel designs capable of damping the downstream growth of the TS wave significantly more than a reference Minature Vortex Generator (MVG) of comparable size. The optimized designs and streaky baseflows they induce are then studied using an energy budget analysis and local stability analysis.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106680"},"PeriodicalIF":2.5,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222284","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

Extension of surface tension model in phase interface tracking method for liquid-gas two-phase flow using unstructured meshes 用非结构网格扩展液气两相流相界面跟踪方法中的表面张力模型

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-03 DOI: 10.1016/j.compfluid.2025.106716

Chuang-Yao Zhao , Jia-Yu Mao , Jun-Min Jiang , Di Qi , Fang-Fang Zhang , Qing Liu , Wei Xiao , Pu-Hang Jin , Kong Ling

{"title":"Extension of surface tension model in phase interface tracking method for liquid-gas two-phase flow using unstructured meshes","authors":"Chuang-Yao Zhao , Jia-Yu Mao , Jun-Min Jiang , Di Qi , Fang-Fang Zhang , Qing Liu , Wei Xiao , Pu-Hang Jin , Kong Ling","doi":"10.1016/j.compfluid.2025.106716","DOIUrl":"10.1016/j.compfluid.2025.106716","url":null,"abstract":"<div><div>Accurate calculation of surface tension plays a crucial role in interface-tracking computational fluid dynamics (CFD) simulations involving liquid-gas interfaces. This article extends the Continuum Surface Stress (CSS) model within the scheme of the Compressed Interface Capturing Scheme for Arbitrary Meshes (CICSAM) to enhance surface tension calculations, with numerical discretization details provided. Comparative studies between the CSS model and the widely used Continuum Surface Force (CSF) model are conducted, focusing on test cases involving droplet equilibrium and bubble rise in both structured and unstructured mesh scenarios. The results indicate that at small Laplace numbers (<em>La</em>), the CSS model substantially suppresses spurious currents, producing maximum velocity magnitudes that are 1.5 to 2.0 times lower than those of the CSF model for an equilibrium droplet case. Conversely, under conditions with large <em>La</em>, the CSF model yields smaller spurious currents, confirming its superior performance in the regime and aligning with trends in the literature. Notably, under conditions with large <em>La</em>, the CSS model prevents droplet disintegration and interface disturbances, thereby preserving the static droplet morphology. Furthermore, the CSS model predicts bubble dynamics with greater accuracy across various mesh types, maintaining precision even on coarser meshes. The application of this extended model to the simulation of a droplet generator and double bubble coalescence further validates its capability to produce reliable predictions, outperforming the CSF model. These findings underscore the CSS model's potential to enhance the simulation of complex liquid-gas flows, offering a robust solution for computational fluid dynamics in engineering applications.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106716"},"PeriodicalIF":2.5,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242439","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

Quantum collision circuit, quantum invariants and quantum phase estimation procedure for fluid dynamic lattice gas automata 量子碰撞电路，量子不变量和流体动力点阵气体自动机的量子相位估计程序

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-02 DOI: 10.1016/j.compfluid.2025.106688

Niccolò Fonio , Pierre Sagaut , Giuseppe Di Molfetta

{"title":"Quantum collision circuit, quantum invariants and quantum phase estimation procedure for fluid dynamic lattice gas automata","authors":"Niccolò Fonio , Pierre Sagaut , Giuseppe Di Molfetta","doi":"10.1016/j.compfluid.2025.106688","DOIUrl":"10.1016/j.compfluid.2025.106688","url":null,"abstract":"<div><div>Lattice Gas Cellular Automata (LGCA) is a classical numerical method widely known and applied to simulate several physical phenomena. In this paper, we study the translation of LGCA on quantum computers (QC) using computational basis encoding (CBE), developing methods for different purposes. In particular, we clarify and discuss some fundamental limitations and advantages in using CBE and quantum walk as streaming procedure. Using quantum walks affect the possible encoding of classical states in quantum orthogonal states, feature linked to the unitarity of collision and to the possibility of getting a quantum advantage. Then, we give efficient procedures for optimizing collisional quantum circuits, based on the classical features of the model. This is applied specifically to fluid dynamic LGCA. Alongside, a new collision circuit for a 1-dimensional model is proposed. We address the important point of invariants in LGCA providing a method for finding how many invariants appear in their QC formulation. Quantum invariants outnumber the classical expectations, proving the necessity of further research. Lastly, we prove the validity of a method for retrieving any quantity of interest based on quantum phase estimation (QPE).</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106688"},"PeriodicalIF":2.5,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230095","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 systematic study on hybrid RANS/LES models for a high-order discontinuous Galerkin scheme 高阶不连续Galerkin格式的混合RANS/LES模型的系统研究

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-06-02 DOI: 10.1016/j.compfluid.2025.106686

Luca Alberti , Emanuele Carnevali , Andrea Crivellini , Gianmaria Noventa

{"title":"A systematic study on hybrid RANS/LES models for a high-order discontinuous Galerkin scheme","authors":"Luca Alberti , Emanuele Carnevali , Andrea Crivellini , Gianmaria Noventa","doi":"10.1016/j.compfluid.2025.106686","DOIUrl":"10.1016/j.compfluid.2025.106686","url":null,"abstract":"<div><div>In this work we investigate the performance of several hybrid RANS/LES models in a high-order discretization framework. Many hybrid models are indeed tailored around finite volume methods, therefore it is of particular interest to examine their performance within the context of high-order schemes. The numerical study is carried out using an incompressible modal Discontinuous Galerkin solver. The assessment includes the two major classes of non-zonal DES-like turbulence models, <em>i.e</em>. DDES and IDDES. Cutting-edge subgrid length scales are tested in an attempt to mitigate the most common problems affecting DES-like hybrid turbulence models, namely the gray area and modeled-stress depletion. The effect of a low-Reynolds correction that acts against the eddy viscosity drop outside of the RANS region is also taken into consideration. The analysis involves the simulation of some baseline flow problems, like the channel flow at <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>=</mo><mrow><mo>{</mo><mn>400</mn><mo>,</mo><mn>5200</mn><mo>}</mo></mrow></mrow></math></span>, the backward-facing step and the flow past a NACA0012 foil at high angle of attack.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106686"},"PeriodicalIF":2.5,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212870","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 interface-fitted/fictitious domain-finite element method for the simulation of particles falling in viscous fluid with contact 粘滞流体中颗粒接触下落模拟的拟合界面/虚拟域有限元方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-05-27 DOI: 10.1016/j.compfluid.2025.106685

Yi Liang , Cheng Wang , Pengtao Sun , Yan Chen , Jiarui Han

{"title":"An interface-fitted/fictitious domain-finite element method for the simulation of particles falling in viscous fluid with contact","authors":"Yi Liang , Cheng Wang , Pengtao Sun , Yan Chen , Jiarui Han","doi":"10.1016/j.compfluid.2025.106685","DOIUrl":"10.1016/j.compfluid.2025.106685","url":null,"abstract":"<div><div>In this paper, an interface-fitted/fictitious domain-finite element method (IF/FD-FEM) is developed to simulate the settling and rebounding processes of rigid particles in viscous fluids. Through local movements of mesh vertices near the moving interface of fluid and rigid particle, a locally moving mesh that fits the interface is obtained at each time step, which allows for large displacements of rigid particle/structure without the need of interpolation, in comparison with the classical (interface-unfitted) fictitious domain method where the interpolation from the fixed fluid mesh to the moving structural mesh is always needed for the unified-field velocity that is defined in the entire domain. On the other hand, in order to capture the dynamics inside the boundary layer near the surface of rigid particle, thereby to improve the solution accuracy near the interface of fluid and rigid particle, the mesh redistribution technique is also crucial to be performed in the region where the interactional/contacting phenomena occur between the rigid particle and fluid/fluid channel wall. Numerical experiments are carried out to validate the effectiveness and accuracy of the proposed numerical methods for the case of rigid particles falling through the fluid channel, where once the rigid particle touches down the bottom of fluid channel, collisions occur by explicitly applying the rebounding forces. Numerical results illustrate that the redistribution of mesh vertices inside the boundary layer exhibits a higher solution accuracy, furthermore, better agreements with physical experimental data in comparison with the existing literature results are also shown in simulating the settling and rebounding process of rigid particles within viscous fluids.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106685"},"PeriodicalIF":2.5,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178454","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

Discontinuous Galerkin method for incompressible viscous flow based on the entropically damped artificial compressibility 基于熵阻尼人工可压缩性的不可压缩粘性流的不连续Galerkin方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-05-26 DOI: 10.1016/j.compfluid.2025.106684

Le-Wen Chen , Yun-Long Liu , Zhao-Li Tian , Qi-Hang Hao , Qi Kong

{"title":"Discontinuous Galerkin method for incompressible viscous flow based on the entropically damped artificial compressibility","authors":"Le-Wen Chen , Yun-Long Liu , Zhao-Li Tian , Qi-Hang Hao , Qi Kong","doi":"10.1016/j.compfluid.2025.106684","DOIUrl":"10.1016/j.compfluid.2025.106684","url":null,"abstract":"<div><div>The entropically damped artificial compressibility (EDAC) method was integrated into the Runge–Kutta discontinuous Galerkin (RKDG) framework to solve incompressible Navier–Stokes equations. The discontinuous Galerkin method (DG) is known for its robustness and compactness, making it an optimal choice for developing high-order numerical methods on unstructured meshes. The EDAC method adds an entropic damping term to the continuity equation of the traditional artificial compressibility method to alleviate pressure fluctuations during computation. This combination enhances numerical stability and improves computational accuracy, especially in capturing smooth and physically accurate pressure fields. The viscous terms of the momentum equations and the entropic damping term of the continuity equation are discretized together using the symmetric interior penalty Galerkin (SIPG) method by introducing the penalty term to ensure the continuity of the interface solution, which allows the framework to maintain numerical stability on unstructured grids and locally refined grids. Next, quadtree adaptive mesh refinement (AMR) technology was incorporated, and guardcells were used to realize data communication among leaf blocks, thereby enhancing the computational efficiency of the framework. Finally, several test cases were conducted to validate the framework’s precision, accuracy, boundary conditions, and effectiveness of the adaptive technology.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106684"},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144185515","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 volume penalization method for acoustic and aeroacoustic simulation of solid and porous bluff bodies 固体和多孔钝体声学和气动声学模拟的体积惩罚方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-05-26 DOI: 10.1016/j.compfluid.2025.106683

Yannick Schubert, Ennes Sarradj, Mathias Lemke

{"title":"A volume penalization method for acoustic and aeroacoustic simulation of solid and porous bluff bodies","authors":"Yannick Schubert, Ennes Sarradj, Mathias Lemke","doi":"10.1016/j.compfluid.2025.106683","DOIUrl":"10.1016/j.compfluid.2025.106683","url":null,"abstract":"<div><div>This work presents a computational method for acoustic and aeroacoustic simulations, using an immersed boundary method to model porous and solid objects. The approach uses a version of the Brinkman-type volume penalization method in combination with an effective volume to solve the full compressible Navier–Stokes equations employing finite-differences in the time domain. The provided framework enables multiple approaches for modeling objects, which are validated and systematically compared in terms of their associated error convergence. Utilizing the effective volume approach allows acoustic simulations to reach up to third-order convergence, enhancing the accuracy of wave propagation modeling. The methodology is demonstrated for the aeroacoustic sound generated by the flow around a porous-coated cylinder at a Reynolds number of <span><math><mrow><mi>R</mi><mi>e</mi><mo>=</mo><mn>99000</mn></mrow></math></span>. A sensitivity study validates the expected importance of the modeling parameters. Results from the three-dimensional simulations involving two porous coatings with each two diameters exhibit good agreement with experimental data, confirming the validity and reliability of the approach.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106683"},"PeriodicalIF":2.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167048","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

Shock stability of a combined method of advection upstream splitting and time-accurate momentum interpolation 平流上游分裂与时准动量插值相结合方法的激波稳定性

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-05-24 DOI: 10.1016/j.compfluid.2025.106702

E. Dick , Y. Moguen

引用次数: 0

Reconstruction-based high-order conservative central difference schemes for the compressible Navier–Stokes equations 基于重构的可压缩Navier-Stokes方程高阶保守中心差分格式

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2025-05-23 DOI: 10.1016/j.compfluid.2025.106682

Weixiong Yuan , Tiegang Liu , Kui Cao , Zhiqiang Zeng , Kun Wang

{"title":"Reconstruction-based high-order conservative central difference schemes for the compressible Navier–Stokes equations","authors":"Weixiong Yuan , Tiegang Liu , Kui Cao , Zhiqiang Zeng , Kun Wang","doi":"10.1016/j.compfluid.2025.106682","DOIUrl":"10.1016/j.compfluid.2025.106682","url":null,"abstract":"<div><div>A class of reconstruction-based high-order conservative central difference schemes (CD) is developed for solving the compressible Navier–Stokes equations in this paper. The discretization of the viscous and heat fluxes in the Navier–Stokes equations involves a two-step process, where the external first derivatives of the viscous terms are disposed in a reconstruction way, and then the interpolation operation is carried out to calculate the internal first derivatives within the same stencil. Two approaches to the interpolation implementation are discussed: one is founded on the conservative variables, while the other is based on the primitive variables. This design can maintain compactness and consistence as in the stencil of the weighted essentially non-oscillatory (WENO) schemes for the inviscid terms. Under the present framework, a sixth-order central difference scheme for the viscous terms is designed with a stencil width that falls within the range of the fifth-order WENO scheme for the inviscid terms. The accuracy for both linear and nonlinear diffusion equations are demonstrated theoretically and the spectral properties are verified via Fourier analysis. Numerous compressible viscous results validate that the present central difference schemes are high-order accurate in smooth regions, easy to implement, robust for the viscous shock simulations and computationally cost-effective.</div></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"299 ","pages":"Article 106682"},"PeriodicalIF":2.5,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144202999","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