Computers & Fluids最新文献_第9页

Lifting relations for a generalized total-energy double-distribution-function kinetic model and their impact on compressible turbulence simulation 广义总能双分布函数动力学模型的提升关系及其对可压缩湍流模拟的影响

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-11 DOI: 10.1016/j.compfluid.2024.106368

Yiming Qi , Jie Shen , Lian-Ping Wang , Zhaoli Guo

{"title":"Lifting relations for a generalized total-energy double-distribution-function kinetic model and their impact on compressible turbulence simulation","authors":"Yiming Qi , Jie Shen , Lian-Ping Wang , Zhaoli Guo","doi":"10.1016/j.compfluid.2024.106368","DOIUrl":"10.1016/j.compfluid.2024.106368","url":null,"abstract":"<div><p>Recently, Qi et al. (2022) and Guo et al. (2023) proposed two alternative designs of an efficient mesoscopic method using the total-energy double-distribution-function (DDF) formulation, hereafter referred to as the Qi model and the Guo model. The two models share the same advantage of using only 40 discrete particle velocities to fully reproduce the Navier–Stokes-Fourier (NSF) system. However, the Guo model is based on a more rigorous kinetic consideration, while the Qi model relies on a more general design of the source term to allow for adjustable bulk-to-shear viscosity ratio. In this paper, we derive lifting relations for the Qi model based on two alternative approaches, namely, the Hermite expansion and the Chapman–Enskog expansion, which can be used to construct the boundary and initial conditions for the mesoscopic method. For three-dimensional compressible turbulence simulations, including compressible decaying homogeneous isotropic turbulence and Taylor–Green vortex flows, the derived two sets of lifting relations are applied to the initialization distribution function to study their impacts. Interestingly, for the Qi model, the two sets of lifting relations yield the same results without numerical artifacts, whereas for the Guo model, an appropriate lifting relation must be specified to avoid numerical artifacts resulting from the flow initialization (Qi et al., 2023).</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106368"},"PeriodicalIF":2.5,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141637544","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

Accurate numerical prototypes of microfluidic droplet generators with open source tools 利用开源工具制作微流控液滴发生器的精确数值原型

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-11 DOI: 10.1016/j.compfluid.2024.106366

David Gabriel Harispe, Pablo A. Kler

引用次数: 0

An efficient hybrid WENO scheme with minimized dispersion and adaptive dissipation properties for compressible flows 针对可压缩流的具有最小分散和自适应耗散特性的高效混合 WENO 方案

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-11 DOI: 10.1016/j.compfluid.2024.106363

Yin Zhang , Yujie Zhu , Zhensheng Sun , Siye Li , Yu Hu , Xuefeng Xia , Wei Zhang

{"title":"An efficient hybrid WENO scheme with minimized dispersion and adaptive dissipation properties for compressible flows","authors":"Yin Zhang , Yujie Zhu , Zhensheng Sun , Siye Li , Yu Hu , Xuefeng Xia , Wei Zhang","doi":"10.1016/j.compfluid.2024.106363","DOIUrl":"10.1016/j.compfluid.2024.106363","url":null,"abstract":"<div><p>A numerical scheme with good spectral properties is important for the simulation of compressible flows with various of length scales for fine flow scales resolving. The MDAD-HY scheme (Li et al., 2022) using a discontinuity detector and scale sensor achieves the minimized dispersion and adaptive dissipation property. However, the discontinuity detector is devised based on the ratio of the 1st-order and 2nd-order derivatives on two sides of the interface introducing excessive numerical cost. To address this issue, an efficient hybrid WENO scheme with minimized dispersion and adaptive dissipation properties is proposed in this work. Based on the characteristic-decomposition approach, the numerical flux of the present hybrid scheme is achieved by switching between the linear MDAD scheme and the MDAD-WENO scheme according to a new efficient non-dimensional discontinuity detector. The linear flux is reconstructed in a component-wise method to decrease the characteristic-projection operations. To further improve the spectral property of the present scheme, an adaptive parameter controlling the contribution of the optimal linear scheme according to the discontinuity indicator is introduced. Several benchmark test cases involving broadband of length scales and discontinuities are adopted to verify the efficiency and the high-resolution capability of the present scheme.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106363"},"PeriodicalIF":2.5,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141637545","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

The effects of energy accommodation of reflected gas molecules on flow structures during expired spacecraft reentry 过气航天器再入大气层时反射气体分子的能量容纳对流动结构的影响

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-10 DOI: 10.1016/j.compfluid.2024.106362

Yong-Dong Liang , Zhi-Hui Li , Jie Liang , Jia-Zhi Hu

{"title":"The effects of energy accommodation of reflected gas molecules on flow structures during expired spacecraft reentry","authors":"Yong-Dong Liang , Zhi-Hui Li , Jie Liang , Jia-Zhi Hu","doi":"10.1016/j.compfluid.2024.106362","DOIUrl":"10.1016/j.compfluid.2024.106362","url":null,"abstract":"<div><p>To study the influence of energy accommodation of scattering gas molecules on flow fields during large expired spacecraft reentry, a more elaborated gas-surface interaction model, compared with full Maxwellian diffuse model, is employed in implicit algorithms based on Boltzmann model equation. The characteristic distributions around cylinder at different fluid regimes are accordingly obtained by implicit algorithms, Navier-Stokes solver and DSMC ((Direct Simulation Monte Carlo) method. And the consistency of these results is verified. It is confirmed that present algorithms are capable of solving external flow problems covering various fluid regimes. Then the simulation results see that under current conditions set in the paper, pressure and temperature are proportional to wall activation (<span><math><mrow><mi>ω</mi><mo>=</mo><mrow><msub><mi>T</mi><mi>w</mi></msub><mo>/</mo><msub><mi>T</mi><mi>∞</mi></msub></mrow></mrow></math></span>, <span><math><msub><mi>T</mi><mi>w</mi></msub></math></span> is surface temperature, <span><math><msub><mi>T</mi><mi>∞</mi></msub></math></span> denotes as free stream temperature), but their amplitudes alter with <span><math><mi>ω</mi></math></span> at different fluid regimes. As for the effects of energy accommodation coefficients (<span><math><msub><mi>α</mi><mi>e</mi></msub></math></span>), both pressure and temperature profiles vary in a linear way with <span><math><msub><mi>α</mi><mi>e</mi></msub></math></span>. However, the variation ranges of these parameters are diverse with regard to different fluid regimes. These observations are favor to the construction of efficient forecasting software, which could predict the flight path of large defunct spacecraft. In this forecasting software, the external ballistics computations and aerothermodynamic simulations are synchronously carried out.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"281 ","pages":"Article 106362"},"PeriodicalIF":2.5,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694041","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 LSTM-enhanced surrogate model to simulate the dynamics of particle-laden fluid systems 模拟含颗粒流体系统动力学的 LSTM 增强代用模型

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-06 DOI: 10.1016/j.compfluid.2024.106361

Arash Hajisharifi , Rahul Halder , Michele Girfoglio , Andrea Beccari , Domenico Bonanni , Gianluigi Rozza

{"title":"An LSTM-enhanced surrogate model to simulate the dynamics of particle-laden fluid systems","authors":"Arash Hajisharifi , Rahul Halder , Michele Girfoglio , Andrea Beccari , Domenico Bonanni , Gianluigi Rozza","doi":"10.1016/j.compfluid.2024.106361","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106361","url":null,"abstract":"<div><p>The numerical treatment of fluid–particle systems is a very challenging problem because of the complex coupling phenomena occurring between the two phases. Although an accurate mathematical modelling is available to address this kind of applications, the computational cost of the numerical simulations is very expensive. The use of the most modern high performance computing infrastructures could help to mitigate such an issue but not completely to fix it. In this work we develop a non intrusive data-driven reduced order model (ROM) for Computational Fluid Dynamics (CFD) - Discrete Element Method (DEM) simulations. The ROM is built using the proper orthogonal decomposition (POD) for the computation of the reduced basis space and the Long Short-Term Memory (LSTM) network for the computation of the reduced coefficients. We are interested to deal both with system identification and prediction. The most relevant novelties rely on (i) a filtering procedure of the full order snapshots to reduce the dimensionality of the reduced problem and (ii) a preliminary treatment of the particle phase. The accuracy of our ROM approach is assessed against the classic Goldschmidt fluidized bed benchmark problem. Finally, we also provide some insights about the efficiency of our ROM approach.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106361"},"PeriodicalIF":2.5,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607102","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

Gradient-based polynomial adaptation indicators for high-order methods 基于梯度的高阶方法多项式适应指标

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-07-02 DOI: 10.1016/j.compfluid.2024.106360

Christina Kolokotronis, Brian C. Vermeire

{"title":"Gradient-based polynomial adaptation indicators for high-order methods","authors":"Christina Kolokotronis, Brian C. Vermeire","doi":"10.1016/j.compfluid.2024.106360","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106360","url":null,"abstract":"<div><p>This work introduces two new non-dimensional gradient-based adaptation indicators for feature-based polynomial adaptation with high-order unstructured methods when used for turbulent flows. Recently, the Flux Reconstruction (FR) approach has been introduced as a unifying framework for high-order unstructured spatial discretizations. To achieve high-order accuracy, FR utilizes an element-wise polynomial representation of the solution. In the current work, we consider three indicators for local adaptation of this polynomial degree. One, introduced previously, uses a non-dimensional maximal vorticity norm. Two new indicators are then introduced using the Frobenius norm of the velocity gradient, and the eigenvalue modulus of the velocity gradient, both normalized by the maximum local grid spacing and free stream velocity. These feature-based methods are simple to implement and have the potential to track small-scale turbulent structures that arise in scale-resolving simulations, such as Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES). The vorticity, gradient, and eigenvalue-based polynomial adaptation strategies with the FR approach are used to solve the compressible Navier–Stokes equations. DNS simulations are performed for unsteady laminar flow over a two-dimensional circular cylinder, turbulent flow over a three-dimensional sphere, and massively separated flow over a Martian helicopter rotor airfoil section. Results show a reduction in computational cost, with approximately one-quarter of the number of degrees of freedom relative to a non-adaptive case. The Frobenius norm method performs consistently well for all applications, and is identified as being a preferred method when compared to the vorticity and maximum eigenvalue approaches.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106360"},"PeriodicalIF":2.5,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001920/pdfft?md5=c059e203b4c7d93a0ea755a7cfe90303&pid=1-s2.0-S0045793024001920-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607104","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

Exploring the potential of TENO and WENO schemes for simulating under-resolved turbulent flows in the atmosphere using Euler equations 探索 TENO 和 WENO 方案在使用欧拉方程模拟大气中欠解湍流方面的潜力

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-29 DOI: 10.1016/j.compfluid.2024.106349

A. Navas-Montilla, J. Guallart, P. Solán-Fustero, P. García-Navarro

{"title":"Exploring the potential of TENO and WENO schemes for simulating under-resolved turbulent flows in the atmosphere using Euler equations","authors":"A. Navas-Montilla, J. Guallart, P. Solán-Fustero, P. García-Navarro","doi":"10.1016/j.compfluid.2024.106349","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106349","url":null,"abstract":"<div><p>This paper focuses on the design and analysis of very high-order finite volume methods for the computation of simplified meso- and micro-scale atmospheric flows. In a dry atmosphere, these flows can be represented by the Euler equations with a gravitational source term. Two different approaches are considered here. While one of the approaches is fully conservative for the total energy, the other is formulated in a non-conservative form. The main focus of the paper is to analyze the performance of such models in combination with the traditional WENO reconstruction and the novel TENO reconstruction by examining the spectral properties of these reconstruction methods. The overarching goal is to determine whether the combination of these models and numerical schemes can be used to build an implicit Large Eddy Simulation framework, shedding light on their potential advantages or limitations in representing under-resolved atmospheric processes in the meso- and micro-scales.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106349"},"PeriodicalIF":2.5,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001816/pdfft?md5=0b226165687261fb653604b60e4ac2f2&pid=1-s2.0-S0045793024001816-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541913","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

Lattice Boltzmann simulation of flow boiling heat transfer process in a horizontal microchannel with rectangular cavities 带矩形腔的水平微通道中流动沸腾传热过程的格子波兹曼模拟

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-29 DOI: 10.1016/j.compfluid.2024.106350

Jie Li , Lin Zheng , Hutao Cui

{"title":"Lattice Boltzmann simulation of flow boiling heat transfer process in a horizontal microchannel with rectangular cavities","authors":"Jie Li , Lin Zheng , Hutao Cui","doi":"10.1016/j.compfluid.2024.106350","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106350","url":null,"abstract":"<div><p>Bubble nucleation, growth and separation from cavities on the bottom of a microchannel for subcooled flow boiling are investigated by pseudo-potential lattice Boltzmann method. The influence of subcooling temperature, wall superheat, wettability, cavity size, and cavity number on the flow boiling heat transfer is systematically studied. The results show that the bubble equivalent diameter is 1.9 times larger at subcooling temperature 0.05<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span> than that at 0.15<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span>, and the heat flux is also 8 % higher at subcooling temperature 0.05<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span> than that at 0.15<span><math><msub><mi>T</mi><mi>c</mi></msub></math></span>. It is found that the flow boiling changes from nucleate boiling to film boiling with the increase of wall superheat. When the wall wettability changes from the hydrophobic wall (<em>θ</em> = 120°) to the hydrophilic wall (<em>θ</em> = 30°), the average Nusselt number (<em>Nu<sub>av</sub></em>) is reduced by 23 %. We also optimize cavity height and the uniformly distributed cavity number in the microchannel. It is found that the <em>Nu<sub>av</sub></em> is increased by 9.7 % when the cavity height changes from <em>h</em> = 20lu (lattice unit) to <em>h</em> = 60lu. However, there exists an optimal cavity height about <em>h</em> = 60lu, where the heat transfer performance cannot be improved with the cavity height over this value. In addition, the number of cavities in the microchannel can improve the boiling heat transfer. When the cavity number changes from 1 to 4, the <em>Nu<sub>av</sub></em> is increased by 10 %.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106350"},"PeriodicalIF":2.5,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479346","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 Poisson-bracket scheme for nonlinear shallow-water sloshing in an oscillating tank with irregular bottom surface 不规则底面振荡槽中非线性浅水荡动的泊松支架方案

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-29 DOI: 10.1016/j.compfluid.2024.106353

Hamid Alemi Ardakani , Thomas J. Bridges

{"title":"A Poisson-bracket scheme for nonlinear shallow-water sloshing in an oscillating tank with irregular bottom surface","authors":"Hamid Alemi Ardakani , Thomas J. Bridges","doi":"10.1016/j.compfluid.2024.106353","DOIUrl":"https://doi.org/10.1016/j.compfluid.2024.106353","url":null,"abstract":"<div><p>The mass-, energy-, and potential-enstrophy-conserving Poisson bracket numerical scheme introduced by Arakawa & Lamb (1981), and extended by Salmon (2004) and Stewart & Dellar (2016), is adapted to the problem of nonlinear shallow-water sloshing over a <em>variable bottom surface</em> in a rigid rectangular basin undergoing a prescribed <em>coupled surge-sway motion</em>. Adaptation to a finite domain requires a new approach to the boundary conditions at solid boundaries in the context of the Arakawa C grid. In this paper, the boundary condition at the vertical walls is taken to be vanishing of the normal derivative of the tangential velocity. This gives zero potential vorticity at the boundary, and is consistent with the material conservation of the potential vorticity. This condition, coupled to symmetric boundary conditions for the wave height arising from a reduced version of the evolution equations at boundaries, leads to an extension of the class of staggered C-grid Poisson-bracket schemes to interior flows with solid boundaries. The scheme is implemented, shown to preserve Casimirs, and applied to a range of problems in shallow water hydrodynamics including interaction of travelling hydraulic jumps at resonance, and X-type soliton interactions over a variable bottom surface. This structure-preserving scheme provides a robust building block for long-time simulation of floating ocean wave energy extractors.</p></div>","PeriodicalId":287,"journal":{"name":"Computers & Fluids","volume":"280 ","pages":"Article 106353"},"PeriodicalIF":2.5,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045793024001853/pdfft?md5=7d3ad02036b53c631d85746e954d56af&pid=1-s2.0-S0045793024001853-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141541917","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

Interface capturing schemes based on sigmoid functions 基于sigmoid函数的界面捕捉方案

IF 2.5 3区工程技术

Computers & Fluids Pub Date : 2024-06-28 DOI: 10.1016/j.compfluid.2024.106352

Ke Zhang, Yiqing Shen

引用次数: 0