arXiv 1402.47922014-02-19physics.flu-dynnlin.CD

An accurate and efficient Lagrangian sub-grid model

I. M. Mazzitelli, F. Toschi, A. S. Lanotte

DOI：: 10.1063/1.4894149

英文摘要：

A computationally efficient model is introduced to account for the sub-grid scale velocities of tracer particles dispersed in statistically homogeneous and isotropic turbulent flows. The model embeds the multi-scale nature of turbulent temporal and spatial correlations, that are essential to reproduce multi-particle dispersion. It is capable to describe the Lagrangian diffusion and dispersion of temporally and spatially correlated clouds of particles. Although the model neglects intermittent corrections, we show that pair and tetrad dispersion results nicely compare with Direct Numerical Simulations of statistically isotropic and homogeneous $3D$ turbulence. This is in agreement with recent observations that deviations from self-similar pair dispersion statistics are rare events.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

阅读原文

阅读 PDF ↗

arXiv 页面 ↗HTML 原文 ↗

本文内容

英文摘要相关论文

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

继续探索

相关论文

Grid-based calculation of Lagrangian mean

Lagrangian averaging has been shown to be more effective than Eulerian mean in separating waves from slow dynamics in two-timescale flows. It also appears in many reduced models that capture the wave feedback on the slow flow. Its calculation, however, requires tracking particles in time, which imposes several difficulties in grid-based numerical simulations or estimation from fixed-point measurements. To circumvent these difficulties, we propose a grid-based iterative method to calculate Lagrangian mean without tracking particles in time. We explain how this method reduces computation, memory…

2022-03-08physics.flu-dyn

Improving the staggered grid Lagrangian hydrodynamics for modeling multi-material flows

In this work, we make two improvements on the staggered grid hydrodynamics (SGH) Lagrangian scheme for modeling 2-dimensional compressible multi-material flows on triangular mesh. The first improvement is the construction of a dynamic local remeshing scheme for preventing mesh distortion. The remeshing scheme is similar to many published algorithms except that it introduces some special operations for treating grids around multi-material interfaces. This makes the simulation of extremely deforming and topology-variable multi-material processes possible, such as the complete process of a heavy …

2017-07-07physics.comp-phphysics.flu-dyn

Eulerian and Lagrangian second-order statistics of superfluid ${^4}$He grid turbulence

We use particle tracking velocimetry to study Eulerian and Lagrangian second-order statistics of superfluid $^4$He grid turbulence. The Eulerian energy spectra at scales larger than the mean distance between quantum vortex lines behave classically with close to Kolmogorov-1941 scaling and are almost isotropic. The Lagrangian second-order structure functions and frequency power spectra, measured at scales comparable with the intervortex distance, demonstrate a sharp transition from nearly-classical behavior to a regime dominated by the motion of quantum vortex lines. Employing the homogeneity o…

2021-03-29cond-mat.otherphysics.flu-dyn

Eulerian-Lagrangian method for simulation of cloud cavitation

We present a coupled Eulerian-Lagrangian method to simulate cloud cavitation in a compressible liquid. The method is designed to capture the strong, volumetric oscillations of each bubble and the bubble-scattered acoustics. The dynamics of the bubbly mixture is formulated using volume-averaged equations of motion. The continuous phase is discretized on an Eulerian grid and integrated using a high-order, finite-volume weighted essentially non-oscillatory (WENO) scheme, while the gas phase is modeled as spherical, Lagrangian point-bubbles at the sub-grid scale, each of whose radial evolution is …

2017-12-05physics.flu-dyn

A hybrid Lagrangian -- Eulerian flow solver applied to elastically mounted cylinders in tandem arrangement

The fluid structure interaction of cylinders in tandem arrangement is used as validation basis of a multi-domain Lagrangian-Eulerian hybrid flow solver. In this hybrid combination, separate grids of limited width are defined around every solid body, on which the Eulerian flow equations are solved using finite volume approximations. In order to interconnect the domains defined by the grids, the entire flow is described in Lagrangian coordinates and the corresponding equations are solved via particle approximations in fully coupled mode with the solutions within the Eulerian grids. The flow solv…

2022-07-07physics.flu-dyn

A Stochastic Lagrangian Basis for a Probabilistic Parameterization of Moisture Condensation in Eulerian Models

In this paper we describe the construction of an efficient probabilistic parameterization that could be used in a coarse-resolution numerical model in which the variation of moisture is not properly resolved. An Eulerian model using a coarse-grained field on a grid cannot properly resolve regions of saturation---in which condensation occurs---that are smaller than the grid boxes. Thus, in the absence of a parameterization scheme, either the grid box must become saturated or condensation will be underestimated. On the other hand, in a stochastic Lagrangian model of moisture transport, trajector…

2018-10-27physics.ao-phphysics.flu-dynphysics.geo-ph

更多相关论文收起更多论文

An explicit semi-Lagrangian, spectral method for solution of Lagrangian transport equations in Eulerian-Lagrangian formulations

An explicit high order semi-Lagrangian method is developed for solving Lagrangian transport equations in Eulerian-Lagrangian formulations. To ensure a semi-Lagrangian approximation that is consistent with an explicit Eulerian, discontinuous spectral element method (DSEM) discretization used for the Eulerian formulation, Lagrangian particles are seeded at Gauss quadrature collocation nodes within an element. The particles are integrated explicitly in time to obtain an advected polynomial solution at the advected Gauss quadrature locations. This approximation is mapped back in a semi-Lagrangian …

2019-10-15cs.NAmath.NAphysics.flu-dyn

Lagrangian chaos and turbulent diffusivity

Passive scalar mixing, produced by Lagrangian chaos generated a) by quasi-periodic (integrable) motion of three quasi-point vortices and b) by chaotic motion of three and six quasi-point vortices, has been studied and compared with turbulent mixing of passive scalar in 2D and 3D steady isotropic homogeneous turbulence and in turbulent wakes behind grid and behind cylinder. Results of numerical and laboratory experiments have been used and effective diffusivity approximation as well as distributed chaos approach have been applied to this problem.

2019-04-11physics.flu-dyn

利用机器学习技术对拉格朗日粒子追踪中的湍流场进行去滤波

Defiltering turbulent flow fields for Lagrangian particle tracking using machine learning techniques

本文提出一种基于机器学习的湍流速度去滤波方法，用于改善粗网格流场中的拉格朗日粒子追踪，并在不同滤波尺寸下验证了其对速度脉动、轨迹和沉积速度的重建精度与泛化能力。

2024-11-07physics.flu-dyn

Sensitivity and robustness of Lagrangian coherent structures in coastal water systems

In coastal water systems, horizontal chaotic dispersion plays a significant role in the distribution and fate of pollutants. Lagrangian Coherent Structures (LCSs) provide useful tools to approach the problem of the transport of pollutants and have only recently been applied to coastal waters. While the fundamentals of the LCS approach using idealised analytical flow fields are well established in the literature, there are limited studies on their practical implementations in coastal waters where effects of boundaries and bathymetry frequently become significant. Due to their complex bathymetry…

2021-02-10physics.ao-phphysics.flu-dyn

DeepLag：发现深度拉格朗日动力学以实现直观的流体预测

DeepLag: Discovering Deep Lagrangian Dynamics for Intuitive Fluid Prediction

Tsinghua University（清华大学）

针对欧拉视角下流体动力学难以预测的问题，提出DeepLag方法，通过追踪自适应采样关键粒子发现隐藏拉格朗日动力学，结合拉格朗日与欧拉信息实现高效可解释的流体预测，在多类任务中表现优异。

2024-11-02cs.LGphysics.flu-dyn

LEMDA：一种拉格朗日-欧拉多尺度数据同化框架

LEMDA: A Lagrangian-Eulerian Multiscale Data Assimilation Framework

本文提出LEMDA框架，结合拉格朗日与欧拉观测，利用解析公式实现多尺度湍流数据同化，兼具精确性与高效性。

2024-02-04math.DSphysics.flu-dyn

可压缩粘性流体流动的半隐式拉格朗日Voronoi逼近方法

Semi-Implicit Lagrangian Voronoi Approximation for Compressible Viscous Fluid Flows

本文提出SILVA方法，将拉格朗日Voronoi格式与半隐式积分器结合，用于可压缩粘性流动，在低马赫数下放宽时间步限制并保持正确数值粘性标度，并通过多种含激波和多相流的算例验证其有效性。

2024-10-18cs.NAmath.NAphysics.flu-dyn

颗粒流欧拉-拉格朗日模拟的粗粒化算法

Coarse-graining Algorithms for the Eulerian-Lagrangian Simulation of Particle-laden Flows

本文提出颗粒流欧拉-拉格朗日模拟的新型粗粒化算法（含RKPM变体与扩展DTSM），经基准测试验证一阶RKPM精度最优，扩展DTSM为大规模问题的经济替代方案。

2025-11-11physics.flu-dyn

一种用于稠密颗粒载流的混合浸入边界方法

A hybrid immersed boundary method for dense particle-laden flows

提出混合浸入边界方法HyBM，通过在近颗粒或域壁处采用非对称插值/扩散支撑、其余位置保持经典对称格式，提升稠密颗粒载流模拟精度。

2023-01-31physics.comp-phphysics.flu-dyn

High-order overset grid method for detecting particle impaction on a cylinder in a cross flow

An overset grid method was used to investigate the interaction between a particle-laden flow and a circular cylinder. The overset grid method was implemented in the Pencil Code , a high-order finite-difference code for compressible flow simulation. High-order summation-by-part operators were used at the cylinder boundary, and both bi-linear Lagrangian and bi-quadratic spline interpolation was used to communicate between the background grid and the body-conformal cylindrical grid. The performance of the overset grid method was assessed to benchmark cases of steady and unsteady flows past a cyli…

2018-07-03physics.comp-phphysics.flu-dyn

基于多块重叠网格的高保真高效点粒子直接数值模拟框架

A high-fidelity and efficient framework for point-particle direct numerical simulation based on multi-block overset grids

本文提出基于多块重叠网格的高保真高效点粒子直接数值模拟框架，通过块间映射与快速搜索定位优化粒子追踪，实现复杂几何中大规模粒子模拟，并验证其在压气机叶栅中的适用性。

2025-09-09physics.flu-dyn

Lagrangian filtered density function for LES-based stochastic modelling of turbulent dispersed flows

The Eulerian-Lagrangian approach based on Large-Eddy Simulation (LES) is one of the most promising and viable numerical tools to study turbulent dispersed flows when the computational cost of Direct Numerical Simulation (DNS) becomes too expensive. The applicability of this approach is however limited if the effects of the Sub-Grid Scales (SGS) of the flow on particle dynamics are neglected. In this paper, we propose to take these effects into account by means of a Lagrangian stochastic SGS model for the equations of particle motion. The model extends to particle-laden flows the velocity-filte…

2016-07-07physics.flu-dyn

一种用于流体和粒子动力学的耦合欧拉-拉格朗日方法

A coupled Eulerian Lagrangian approach for fluid and particle dynamics

Institute for Plasma Research（等离子体研究所）；Homi Bhabha National Institute（霍米·巴巴国立学院）

该研究提出用于模拟二维不可压缩流中流体与粒子动力学的耦合欧拉-拉格朗日计算框架，扩展了GPU加速求解器，通过特定格式积分方程、插值实现耦合，经多种验证，具有计算效率高、扩展性稳定等优势，适用于相关研究。

2026-07-21physics.flu-dyn