Article
Physics, Fluids & Plasmas
Marie-Luise Maier, Ravi A. Patel, Nikolaos Prasianakis, Sergey Churakov, Hermann Nirschl, Mathias J. Krause
Summary: Reactive particulate systems play a crucial role in process engineering applications, and modeling can be a powerful tool for optimizing process conditions. The study introduces a new generic modeling framework using a combination of lattice Boltzmann method and discrete-element method to capture relevant aspects of reactive particle fluid flows.
Article
Mechanics
Japinder S. Nijjer, Duncan R. Hewitt, Jerome A. Neufeld
Summary: This study investigates miscible displacements in 2D homogeneous porous media, considering the viscosity ratio, density variations, and background flow represented by the Peclet number. The dynamics evolve through nine regimes, involving processes like longitudinal diffusion, vertical flow, and gravity currents. Simplified models are developed to describe the evolution of the concentration field in each regime. Three case studies are also conducted to illustrate the physical balances in CO2 geological storage.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Y. Elgahawy, J. Azaiez
Summary: This study investigates buoyancy-driven instabilities in horizontally layered heterogeneous porous media through numerical simulations. The effects of different permeability distributions on fluid flow are analyzed under scenarios of density mismatches, revealing qualitative and quantitative characteristics. Overall, heterogeneity induces more diffuse finger structures compared to homogeneous cases, with trends in instability onset time, flow mixing, and stability varying based on permeability distributions and number of layers.
Article
Mechanics
M. Schiodt, A. Hodzic, F. Evrard, M. Hausmann, B. Van Wachem, C. M. Velte
Summary: This study demonstrates that Particle Proper Orthogonal Decomposition (PPOD) is a method for extracting temporal statistical information on dispersed phases in multiphase flows. The results show that PPOD modes can capture both large and small scale flow features, and it provides the possibility of modal analysis of fluid-particle interactions in multiphase flows.
Article
Mechanics
Tianshu Liu, Tao Chen, David M. Salazar, Massimo Miozzi
Summary: The relationship between skin friction and surface optical flow in viscous flows is discussed. The optical flow method is applied to visualize surface temperature and mass transfer, and extract skin friction fields in experiments.
Article
Mechanics
Zhi-Qiang Dong, Lian-Ping Wang, Cheng Peng, Tao Chen
Summary: This study focuses on the application of bounce-back schemes in the lattice Boltzmann method (LBM). It explores the potential errors associated with the reconstruction of unknown distribution functions at boundary nodes using bounce-back schemes. The study demonstrates the importance of relaxation parameters in collision models in determining the magnitude of these errors and proposes an optimal setting to suppress or eliminate most of the undesirable effects. Numerical benchmark studies confirm the effectiveness of the proposed theoretical analysis in improving simulation results.
Article
Mechanics
Tao Chen, Tianshu Liu
Summary: Lie derivative is evaluated and interpreted in relation to fundamental surface physical quantities in near-wall incompressible viscous flows, providing insights into boundary vorticity dynamics and near-wall flow physics. The Lie derivatives are found to be directly associated with boundary enstrophy flux and orthogonal pairs of skin friction, surface vorticity, surface enstrophy gradient, and its conjugate vector.
Article
Mechanics
Gerardo Severino
Summary: The study investigates the dispersion mechanism in a porous formation with steady doublet-type flow, using spatial moments to quantify the process. A simple solution is obtained by adopting simplifying assumptions, showing that dispersion in doublet-type flow is significantly larger than in single line flow.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Meteorology & Atmospheric Sciences
Justin M. Brown, Timour Radko
Summary: Parameterizations of small-scale mixing are crucial for modeling the World Ocean, where larger-scale processes can affect the fluxes of microstructure mixing. The Rocking Ocean Modeling Environment is a new hydrodynamic model that can simulate the effects of certain large-scale processes, such as shear and internal waves, with high accuracy.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2021)
Article
Physics, Fluids & Plasmas
Irina Ginzburg, Goncalo Silva, Francesco Marson, Bastien Chopard, Jonas Latt
Summary: The goal of this work is to improve the existing lattice Boltzmann Dirichlet velocity boundary schemes for inclined walls, curved surfaces, and narrow gaps by enhancing their accuracy, stability, locality, and mass conservation. This is achieved through two infinite-member boundary classes: the LI+ and the EMR. The LI+ class unifies all directional rules and proposes three groups of non-equilibrium local corrections, while the EMR class extends the accuracy to grid-rotated linear Couette flow. Numerical tests are conducted to determine the optimal schemes for creeping and inertial flow regimes.
Article
Mathematics
Yuli D. Chashechkin, Artem A. Ochirov
Summary: This article studies periodic flows in viscous, uniformly stratified fluids, using a system of fundamental equations to describe the transfer of energy, momentum, and matter, and constructing dispersion relations. The study finds that regularly perturbed solutions describe weakly damped waves, while families of singular solutions characterize thin ligaments accompanying each type of wave, which were previously unknown.
Article
Computer Science, Interdisciplinary Applications
Lucie Freret, Michael Williamschen, Clinton P. T. Groth
Summary: This paper presents a parallel anisotropic block-based adaptive mesh refinement (AMR) algorithm for solving physically complex flow problems with highly anisotropic features and varying spatial and temporal scales. The algorithm utilizes a binary tree data structure for anisotropic refinement and coarsening of grid blocks, and employs a non-uniform cell representation to enhance computational efficiency.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Masahiro Kondo, Junichi Matsumoto, Tomohiro Sawada
Summary: A scalable matrix solver was developed for the moving particle hydrodynamics for incompressible flows (MPH-I) method, which can calculate both incompressible and highly viscous flows while ensuring stability through physical consistency. The linear equation in the implicit calculation was converted into a symmetric positive definite (SPD) system to solve only the velocity. Bucket-based multigrid preconditioned CG and CR solvers were developed for scalability.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Engineering, Mechanical
M. Norouzi, S. Dorrani, H. Shokri, O. Anwar Beg
Summary: Investigated thermal viscous fingering instability in anisotropic media using linear stability analysis and computational fluid dynamics (CFD) simulation. Growth rate of disturbances determined by solving quasi-steady-state equations via a shooting method for stability analysis. CFD simulation performed by solving governing equations of heat and mass transfer using a spectral method.
JOURNAL OF ENGINEERING MECHANICS
(2021)
Article
Mechanics
M. Taha, S. Zhao, A. Lamorlette, J. L. Consalvi, P. Boivin
Summary: The pressure-based hybrid lattice-Boltzmann method proposed by Farag et al. was evaluated for simulating buoyancy driven flows. Validation studies on different cases and comparison with experimental results showed good overall agreement in terms of mean and fluctuation quantities, as well as global entrainment.
