Computers & Fluids最新文献_第10页

Positivity-preserving discontinuous spectral element methods for compressible multi-species flows 用于可压缩多物种流动的正保全非连续谱元方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-28 DOI: 10.1016/j.compfluid.2024.106343

Will Trojak , Tarik Dzanic

{"title":"Positivity-preserving discontinuous spectral element methods for compressible multi-species flows","authors":"Will Trojak , Tarik Dzanic","doi":"10.1016/j.compfluid.2024.106343","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106343","url":null,"abstract":"<div><p>We introduce a novel positivity-preserving numerical stabilisation approach for high-order discontinuous spectral element approximations of compressible multi-species flows. The underlying stabilisation method is the adaptive entropy filtering approach (Dzanic and Witherden, <em>J. Comput. Phys.</em>, 468, 2022), which is extended to the conservative formulation of the multi-species flow equations. We show that the straightforward enforcement of entropy constraints in the filter yields poor results around species interfaces and propose an adaptive switch for the entropy bounds based on the convergence properties of the pressure field which drastically improves its performance for multi-species flows. The proposed approach is shown in a variety of numerical experiments applied to the multi-species Euler and Navier–Stokes equations computed on unstructured grids, ranging from shock-fluid interaction problems to three-dimensional viscous flow instabilities. We demonstrate that the approach can retain the high-order accuracy of the underlying numerical scheme even at smooth extrema, ensure the positivity of the species density and pressure in the vicinity of shocks and contact discontinuities, and accurately predict small-scale flow features with minimal numerical dissipation.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106343"},"PeriodicalIF":2.5,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001750/pdfft?md5=8503964f642db3721bae01dc7713b615&pid=1-s2.0-S0045793024001750-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541914","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}

引用次数: 0

Numerical simulation of melt flow and heat transfer in casting filling process based on SPH 基于 SPH 的铸造充填过程中熔体流动和传热的数值模拟

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-28 DOI: 10.1016/j.compfluid.2024.106351

Chen Chen, Yu Sun

{"title":"Numerical simulation of melt flow and heat transfer in casting filling process based on SPH","authors":"Chen Chen, Yu Sun","doi":"10.1016/j.compfluid.2024.106351","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106351","url":null,"abstract":"<div><p>There is a great influence of the melt filling process on the quality of castings. Smoothed particle hydrodynamics (SPH) that materials are approximated by free particles rather than by fixed grids is applied to accurately predict fluid flows involving complex free surfaces. In this paper we present a mathematical model of melt flow and heat transfer by using SPH method. A novel approach is used in the governing equations to ensure stable numerical schemes and homogeneous particle distributions. The SPH heat equation takes into account the thermal release during phase transition and is more suitable for alloy solidification. The solid wall boundary conditions are slightly modified to satisfy the filling simulations. Several case studies are carried out to predict significant details about the filling order and flow structures in the mold cavity. The velocity and temperature distributions during different stages of melt filling are also given. The results show that this proposed model allows us to understand the predisposition of defects such as gas porosity and weld lines in the castings. These predictions can be used as inputs for improving process parameters, venting and cooling systems design.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106351"},"PeriodicalIF":2.5,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541912","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 Lattice Boltzmann Methods based on vector-kinetic models for hyperbolic partial differential equations 基于双曲偏微分方程向量动力学模型的格点玻尔兹曼方法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-24 DOI: 10.1016/j.compfluid.2024.106348

Megala Anandan, S.V. Raghurama Rao

{"title":"On Lattice Boltzmann Methods based on vector-kinetic models for hyperbolic partial differential equations","authors":"Megala Anandan, S.V. Raghurama Rao","doi":"10.1016/j.compfluid.2024.106348","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106348","url":null,"abstract":"<div><p>In this paper, we are concerned about the lattice Boltzmann methods (LBMs) based on vector-kinetic models for hyperbolic partial differential equations. In addition to usual lattice Boltzmann equation (LBE) derived by explicit discretisation of vector-kinetic equation (VKE), we also consider LBE derived by semi-implicit discretisation of VKE and compare the relaxation factors of both. We study the properties such as H-inequality, total variation boundedness and positivity of both the LBEs, and infer that the LBE due to semi-implicit discretisation naturally satisfies all the properties while the LBE due to explicit discretisation requires more restrictive condition on relaxation factor compared to the usual condition obtained from Chapman-Enskog expansion. We also derive the macroscopic finite difference form of the LBEs, and utilise it to establish the consistency of LBEs with the hyperbolic system. Further, we extend this LBM framework to hyperbolic conservation laws with source terms, such that there is no spurious numerical convection due to imbalance between convection and source terms. We also present a D2Q9 model that allows upwinding even along diagonal directions in addition to the usual upwinding along coordinate directions. The different aspects of the results are validated numerically on standard benchmark problems.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106348"},"PeriodicalIF":2.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141595781","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

Jumping behavior of water nanodroplets on a superhydrophobic surface in high Ohnesorge number (Oh) regime 超疏水性表面上纳米水滴在高欧内索尔格数（Oh）状态下的跳跃行为

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-24 DOI: 10.1016/j.compfluid.2024.106344

Ertiza Hossain Shopnil, Md. Nadeem Azad, Jahid Emon, A.K.M. Monjur Morshed

{"title":"Jumping behavior of water nanodroplets on a superhydrophobic surface in high Ohnesorge number (Oh) regime","authors":"Ertiza Hossain Shopnil, Md. Nadeem Azad, Jahid Emon, A.K.M. Monjur Morshed","doi":"10.1016/j.compfluid.2024.106344","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106344","url":null,"abstract":"<div><p>The coalescence-induced jumping of nanodroplets on superhydrophobic surfaces has recently gained research attention due to its application in energy harvesting, self-cleaning, and cooling of nanoscale electronic devices. This study aims to investigate the jumping behavior of water nanodroplets in a high Ohnesorge number regime, where 0.45 <span><math><mo><</mo></math></span> Oh <span><math><mo><</mo></math></span> 1 and identify the critical size of droplets where jumping terminates. The study utilized molecular dynamics simulations to analyze the jumping characteristics of droplets ranging from 1.5 nm to 7 nm in radius. The findings of this research developed a universal jumping mechanism for droplets of all sizes, identified the lower limit of droplet size, below which coalescence-induced jumping does not occur, and explained a special phenomenon of jumping velocity becoming maximum before it approaches zero. The study also investigated how jumping terminates due to the size difference between droplets. These findings align well with prior micro-scale studies and experimental predictions. Surface energy, viscous dissipation, kinetic energy, and varying surface tension have been identified as the dominating factors influencing nanoscale droplet jumping at such a high Oh regime. The findings will provide insights for developing various applications at this scale.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106344"},"PeriodicalIF":2.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479347","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 generation of free-stream turbulence at low Reynolds number: A numerical study 低雷诺数自由流湍流的产生：数值研究

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-24 DOI: 10.1016/j.compfluid.2024.106345

J.M. Catalán , S. Olivieri , M. García-Villalba , O. Flores

{"title":"On the generation of free-stream turbulence at low Reynolds number: A numerical study","authors":"J.M. Catalán , S. Olivieri , M. García-Villalba , O. Flores","doi":"10.1016/j.compfluid.2024.106345","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106345","url":null,"abstract":"<div><p>We investigate the generation of free-stream perturbations at a relatively low characteristic Reynolds number of 1000 by means of direct numerical simulations using a synthetic turbulence generation method. This approach consists of generating turbulent fluctuations by means of digital filtering and a source term formulation in the Navier–Stokes equations. To assess its validity in the framework of decaying turbulence, we compare the results with those obtained with a physically-based, grid-induced turbulent flow in terms of spatial decay, evolution of characteristic length-scales and energy spectra. Also, we highlight relevant differences such as those in the streamwise development length and the anisotropy of the largest scales. Then, we characterize the generated perturbations when systematically varying the input parameters, namely the initial integral length-scale and turbulence intensity. Here, we notice differences in the streamwise decay of the turbulence intensity and the development length as we vary these parameters. By inspecting the evolution of the characteristic length-scales and the micro-scale Reynolds number, we also identify that the effective scale separation is highly sensitive to these variations.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106345"},"PeriodicalIF":2.5,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001774/pdfft?md5=70848ad6aa99dc3d8f6e7e1bdc9a4b64&pid=1-s2.0-S0045793024001774-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479345","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}

引用次数: 0

Direct simulations of external flow and noise radiation using the generalized interpolation-supplemented cascaded lattice Boltzmann method 利用广义插值补充级联晶格玻尔兹曼法直接模拟外部流动和噪声辐射

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-22 DOI: 10.1016/j.compfluid.2024.106347

Jian Song , Fan Zhang , Yuanpu Zhao , Feng Ren , Haibao Hu

{"title":"Direct simulations of external flow and noise radiation using the generalized interpolation-supplemented cascaded lattice Boltzmann method","authors":"Jian Song , Fan Zhang , Yuanpu Zhao , Feng Ren , Haibao Hu","doi":"10.1016/j.compfluid.2024.106347","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106347","url":null,"abstract":"<div><p>Direct simulations of external flow and the associated noise radiation are studied by an improved lattice Boltzmann method, i.e., the generalized interpolation-supplemented cascaded lattice Boltzmann method (GICLBM). In this method, the cascaded collision scheme is used to improve the numerical stability of the conventional collision schemes, and the generalized interpolation approach is used in the particle streaming process so as to allow a non-uniform and body-fitted mesh partition. With that, both near- and far-field flow dynamics and noise radiation are resolved simultaneously. In order to capture sound waves, the perfectly matched layer is also implemented so as to avoid waves reflecting to and polluting the inner acoustic field. Moreover, a novel index technique is developed for the GICLBM to enable implicit streaming, which brings an efficient memory reduction. Three cases are then performed to showcase the feasibility, accuracy, extensibility, and efficiency of the present framework, including flow past a square cylinder, flow past an elliptic cylinder, and flow past a NACA 0012 airfoil, each implemented with a type of body-fitted mesh. Both the fluid dynamic and noise radiation are found to be in good agreement with results using the Navier–Stokes solvers. This study demonstrates the potential of the GICLBM for accurately and efficiently simulating external problems as well as sound generation and propagation.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106347"},"PeriodicalIF":2.5,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541916","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 stable loosely coupled Fluid Structure Interaction scheme using sharp interface immersed boundary method for low to moderate mass ratios 采用尖锐界面沉浸边界法的稳定松耦合流体结构相互作用方案，适用于中低质量比

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-21 DOI: 10.1016/j.compfluid.2024.106342

Nandan Sarkar , Sayantan Dawn , Apurva Raj , Piru Mohan Khan , Somnath Roy

{"title":"A stable loosely coupled Fluid Structure Interaction scheme using sharp interface immersed boundary method for low to moderate mass ratios","authors":"Nandan Sarkar , Sayantan Dawn , Apurva Raj , Piru Mohan Khan , Somnath Roy","doi":"10.1016/j.compfluid.2024.106342","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106342","url":null,"abstract":"<div><p>The stability of fluid–structure interaction (FSI) problems using immersed boundary (IB) method is an active area of research. In this regime, strong coupling is generally used to ensure stability and robustness. Strong coupling, however, is computationally expensive owing to its iterative nature. In the present work, we showcase the application of loose coupling algorithm for FSI problems using the sharp interface IB method specifically for low to moderate mass ratios (defined as the ratio of the mass of the structure to the mass of the fluid at the same volume). We demonstrate several test cases: vortex-induced vibration (VIV) of a cylinder, the effect of hinged leaflets attached to the exit of a piston in a channel, sedimentation of a circular disk, and bi-leaflet mechanical heart valves (BMHV) made of lightweight materials in physiological flow. We found our loose coupling method to be stable in all the test cases and obtained a linear relationship between the grid resolution employed and the lowest mass ratio for stable computations in the case of VIV of cylinder. Thus, a significant finding of our work is that with a reduction in grid spacing, one can achieve stable FSI simulation involving lower mass ratios using loosly-coupled schemes. We have deployed the present technique to investigate the dynamics of very low-density cylinders and hinged leaflets due to the fluid forces on them. The current method is extended to handle flexible bodies, such as vortex-induced vibrations of an elastic plate attached to a rigid cylinder and stable simulations are obtained when the Young’s modulus of the elastic plate is varied.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106342"},"PeriodicalIF":2.5,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607103","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

Accuracy and performance evaluation of low density internal and external flow predictions using CFD and DSMC 利用 CFD 和 DSMC 对低密度内部和外部流动预测的精度和性能进行评估

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-18 DOI: 10.1016/j.compfluid.2024.106346

Surya Kiran Peravali , Vahid Jafari , Amit K. Samanta , Jochen Küpper , Muhamed Amin , Philipp Neumann , Michael Breuer

{"title":"Accuracy and performance evaluation of low density internal and external flow predictions using CFD and DSMC","authors":"Surya Kiran Peravali , Vahid Jafari , Amit K. Samanta , Jochen Küpper , Muhamed Amin , Philipp Neumann , Michael Breuer","doi":"10.1016/j.compfluid.2024.106346","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106346","url":null,"abstract":"<div><p>The Direct Simulation Monte Carlo (DSMC) method was widely used to simulate low density gas flows with large Knudsen numbers. However, DSMC encounters limitations in the regime of lower Knudsen numbers (<span><math><mrow><mi>Kn</mi><mo><</mo><mn>0</mn><mo>.</mo><mn>05</mn></mrow></math></span>). In such cases, approaches from classical computational fluid dynamics (CFD) relying on the continuum assumption are preferred, offering accurate solutions at acceptable computational costs. In experiments aimed at imaging aerosolized nanoparticles <em>in vacuo</em> a wide range of Knudsen numbers occur, which motivated the present study on the analysis of the advantages and drawbacks of DSMC and CFD simulations of rarefied flows in terms of accuracy and computational effort. Furthermore, the potential of hybrid methods is evaluated. For this purpose, DSMC and CFD simulations of the flow inside a convergent–divergent nozzle (internal expanding flow) and the flow around a conical body (external shock generating flow) were carried out. CFD simulations utilize the software OpenFOAM and the DSMC solution is obtained using the software SPARTA. The results of these simulation techniques are evaluated by comparing them with experimental data (1), evaluating the time-to-solution (2) and the energy consumption (3), and assessing the feasibility of hybrid CFD-DSMC approaches (4).</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"279 ","pages":"Article 106346"},"PeriodicalIF":2.5,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001786/pdfft?md5=52837a05ec52af2347a2f62d733bd3dc&pid=1-s2.0-S0045793024001786-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141482986","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}

引用次数: 0

A face-centred finite volume method for laminar and turbulent incompressible flows 层流和不可压缩湍流的面心有限体积法

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-15 DOI: 10.1016/j.compfluid.2024.106339

Luan M. Vieira , Matteo Giacomini , Ruben Sevilla , Antonio Huerta

{"title":"A face-centred finite volume method for laminar and turbulent incompressible flows","authors":"Luan M. Vieira , Matteo Giacomini , Ruben Sevilla , Antonio Huerta","doi":"10.1016/j.compfluid.2024.106339","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106339","url":null,"abstract":"<div><p>This work develops, for the first time, a face-centred finite volume (FCFV) solver for the simulation of laminar and turbulent viscous incompressible flows. The formulation relies on the Reynolds-averaged Navier–Stokes (RANS) equations coupled with the negative Spalart–Allmaras (SA) model and three novel convective stabilisations, inspired by Riemann solvers, are derived and compared numerically. The resulting method achieves first-order convergence of the velocity, the velocity-gradient tensor and the pressure. FCFV accurately predicts engineering quantities of interest, such as drag and lift, on unstructured meshes and, by avoiding gradient reconstruction, the method is less sensitive to mesh quality than other FV methods, even in the presence of highly distorted and stretched cells. A monolithic and a staggered solution strategies for the RANS-SA system are derived and compared numerically. Numerical benchmarks, involving laminar and turbulent, steady and transient cases are used to assess the performance, accuracy and robustness of the proposed FCFV method.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"279 ","pages":"Article 106339"},"PeriodicalIF":2.5,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001713/pdfft?md5=3356200a80dfed7cdee6231056ad6ed1&pid=1-s2.0-S0045793024001713-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141444206","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}

引用次数: 0

Dynamic behavior of floating ferrofluid droplet through an orifice with a magnetic field 浮动铁流体液滴在磁场作用下通过孔口的动力学行为

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-15 DOI: 10.1016/j.compfluid.2024.106341

Zhou Jinxiang , Liming Yang , Yaping Wang , Xiaodong Niu , Jie Wu , Linchang Han , Adnan Khan

{"title":"Dynamic behavior of floating ferrofluid droplet through an orifice with a magnetic field","authors":"Zhou Jinxiang , Liming Yang , Yaping Wang , Xiaodong Niu , Jie Wu , Linchang Han , Adnan Khan","doi":"10.1016/j.compfluid.2024.106341","DOIUrl":"10.1016/j.compfluid.2024.106341","url":null,"abstract":"<div><p>In this study, we utilize the simplified lattice Boltzmann method (SLBM) to investigate numerically the motion of buoyancy-driven deformable ferrofluid droplets through the orifice of varying widths and depths in two-dimensional (2D) space. Positioned directly beneath a plate with a central hole, the magnetic fluid droplets undergo acceleration to meet the plate under the influence of buoyancy and magnetic forces. We investigate the impact of magnetic field strength (<em>Bo<sub>m</sub></em>), pore ratio (PR), plate thickness ratio (WR), droplet viscosity (Re), and the plate's wettability (contact angle) on the dynamic behavior of ferrofluid droplets ascending through the orifice. Our results reveal significant effects on the efficiency and morphology of ferrofluid droplets passing through the hole. The introduction of a magnetic field facilitates a larger volume of liquid droplets passing through the hole at PR = 0.25. Moreover, increasing magnetic field intensity leads to the generation of secondary droplets during passage through the orifice. In practical applications, to prevent the generation of secondary droplets, we recommend <em>Bo<sub>m</sub></em> < 3 when the pore ratio falls within 0.35 < PR < 0.45 and plate thickness ratio WR = 1. Additionally, with increasing obstacle thickness, ferrofluid droplets on the hydrophobic wall can pass through the orifice more easily. Furthermore, when the magnetic field strength exceeds a certain threshold (<em>Bo<sub>m</sub></em> = 6.08), the droplets can pass through the orifice regardless of the wall's hydrophilicity or hydrophobicity. For practical applications with the pore ratio PR = 0.25 and plate thickness ratio WR > 1, we suggest <em>Bo<sub>m</sub></em> > 3.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"279 ","pages":"Article 106341"},"PeriodicalIF":2.5,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141403360","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