Article
Mechanics
J. A. K. Horwitz, G. Iaccarino, J. K. Eaton, A. Mani
Summary: A methodology for simulating two-way coupled particle-laden flows is outlined in this study, which accurately models the interaction between fluid and particles at low particle Reynolds numbers and can be extended to other physics like heat transfer and electromagnetism. By verifying and extending the discrete Green's function method, accurate results for particle-laden flows under different conditions can be obtained.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Guo Chen, Haiou Wang, Kun Luo, Jianren Fan
Summary: In this study, turbulent particle-laden boundary layer combustion over a flat plate is investigated using direct numerical simulation. The effects of particle properties and chemical reactions on particle-wall interactions and turbulence modulation are explored. The study reveals the dominance of particle heat transfer over wall heat transfer in certain conditions, observation of particle accumulation due to turbophoresis effect, and the modulation of flow topologies and Reynolds stress anisotropy by combustion and particles.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Water Resources
Daniel Wildt, Christoph Hauer, Helmut Habersack, Michael Tritthart
Summary: In this study, a Euler-Lagrangian two-way coupled large eddy simulation was used to model the development of sediment plume. The momentum exchange was calculated based on interaction forces in the Maxey-Riley equation. The results were validated against experimental data and showed good agreement. The analysis revealed three phases of sediment plume development: acceleration, transport, and deposition. The significant slowing down of fluid flow and particle sorting were identified as important processes in the initial development of sediment plume, which are not accounted for in one-way coupled models.
ADVANCES IN WATER RESOURCES
(2022)
Article
Mechanics
Marcello Lappa
Summary: This study aims to develop an integrated framework that encompasses earlier discoveries and investigates new effects. The alterations in geometrically perfect particle structures were examined by varying the percentage of dispersed solid mass. The results demonstrate that the back influence of particles on the carrier flow can result in various paths of evolution.
Article
Engineering, Marine
Yujia Wei, Atilla Incecik, Tahsin Tezdogan
Summary: This study numerically investigates the hull girder loads on a flexible containership S175 with intact and damaged conditions in regular head waves. A two-way coupled fluid-structure interactions framework is used, with the interactions between flooding water and wave fields modeled by OpenFOAM and structural deformation predicted using MBDyn. Hydroelasticity computations are performed for two different damage scenarios. The results show that the damaged ship has less vertical motions but greater global wave loads compared to the intact ship. Furthermore, ship damages greatly influence the hull girder vertical bending moments (VBMs), while still water VBM is sensitive to added weight from flooding water. In specific ship-damage conditions, local hogging moments at several amidship sections exceed international regulations. Thus, a new safety factor is recommended to prevent hogging moments of damaged ships from exceeding the limiting value. The results can also aid in the design of future conventional ships by determining whether they will experience secondary damage due to hydroelastic response.
Article
Mechanics
S. Beetham, R. O. Fox, J. Capecelatro
Summary: In this study, model closures for multiphase Reynolds-averaged Navier-Stokes (RANS) equations are developed using sparse regression and Eulerian-Lagrangian simulations to ensure accuracy and robustness of the models across different flow conditions. The focus is on capturing the dynamics of gas-particle flows, particularly the generation of particle clusters and interphase momentum exchange, in a compact and algebraic manner.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Roumaissa Hassaini, Alec J. Petersen, Filippo Coletti
Summary: When inertial particles are dispersed in a turbulent flow at high concentrations, their behavior and the turbulence are profoundly changed. Laboratory measurements reveal that sub-Kolmogorov particles falling in homogeneous air turbulence experience intensified clustering and increased settling rate. This settling enhancement is attributed to the predominantly downward fluid velocity and increased slip velocity between particles and the fluid. The concentrated particles possess a higher effective Stokes number, leading to larger relative velocities and accelerations that may impact inter-particle collision probability.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Ocean
Javad Farrokhi Derakhshandeh
Summary: This study investigates the wake-induced vibration of a self-excitation thin piezoelectric actuator for energy harvesting using vortices energy. The effect of different longitudinal spacing ratios on the actuator is analyzed, and a key spacing ratio is identified. The flexible response and power production of the actuator are explored, and the relationship between vortices frequency and displacement and power production is established. Numerical investigations using two-way fluid-structural interaction are conducted to validate the findings and equations.
APPLIED OCEAN RESEARCH
(2022)
Article
Mechanics
Bogdan Rosa, Szymon Kopec, Ahmad Ababaei, Jacek Pozorski
Summary: Statistical quantities related to the motion of low inertia particles in homogeneous isotropic turbulence are studied through numerical simulations. The results show that the radial distribution function of droplets decreases with increasing mass loading when gravity is not considered, but clustering occurs when gravity is present. The relative velocities increase due to momentum transfer from droplets to the fluid. The settling velocity increases with mass loading and Reynolds number. Parameterization is necessary for simulations of small particles at high mass loadings to reduce computational costs.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Multidisciplinary Sciences
Frederic Daude, Pascal Galon, Afaque Shams
Summary: Fluid-structure interaction in fluid-filled flexible pipelines is modeled using a time explicit nonlinear 1-D coupled approach. The internal fluid is modeled using a homogeneous equilibrium model, while the pipelines' mechanical behavior is obtained following the Euler-Bernoulli beam theory. Radial expansion of the pipe cross section is taken into account, and the coupling between fluid and structure is assessed on various experiments, demonstrating the efficiency and representativeness of the approach.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Mechanics
J. Ocampo Jaimes, F. Graef, L. Zavala Sanson
Summary: In this study, the dispersion of particles in two-dimensional vortices, circular monopoles, and the Chaplygin-Lamb dipole was numerically investigated using a Lagrangian stochastic model. The results show that the dispersion behavior of particles varies depending on the flow patterns.
Article
Physics, Fluids & Plasmas
Steven T. Bramwell
Summary: This paper explores the possibility of establishing an analytic form of the distribution of the order parameter fluctuations in a two-dimensional critical spin-wave model or a two-dimensional Edwards-Wilkinson interface. The results show that the characteristic function of the distribution can be expressed exactly as a gamma function quotient, and a Charlier series using the convolution of two Gumbel distributions as the kernel converges to the exact result over a restricted domain. These findings can also be extended to calculate the temperature dependence of the distribution and provide insight into the origin of Gumbel-like distributions in non-extreme steady-state and equilibrium quantities.
Article
Mechanics
Xiangjun Wang, Minping Wang, Luca Biferale
Summary: This study investigates the accelerations of tracer and light particles in compressible homogeneous isotropic turbulence. The results show that the characteristics of acceleration vary for tracer particles and bubbles, and are closely related to the flow structures.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Linfeng Jiang, Cheng Wang, Shuang Liu, Chao Sun, Enrico Calzavarini
Summary: In this study, we investigate the translational and rotational dynamics of neutrally buoyant finite-size spheroids in hydrodynamic turbulence using numerical simulations. Our results show that the accelerations and rotations of non-spherical particles are influenced by filtered fluid forces and torques, similar to spherical particles. However, the orientations of the particles exhibit preferential alignments with the surrounding flow structures. We also demonstrate the significance of inertial-scale flow structures in the transport of neutrally buoyant bodies within the inertial range.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Aerospace
Jose D. Hoyos, Camilo Echavarria, Juan P. Alvarado, Gustavo Suarez, Juliana A. Nino, Jorge I. Garcia
Summary: An aero-structural algorithm is developed to optimize a flying wing in cruise conditions by integrating the structure and aerodynamics. The algorithm employs a particle swarm optimization routine to reduce the weight and aerodynamic drag, evaluating different shapes until reaching the optimal wing parameters. The results show that combining reflex airfoils and sweep with washout is the optimal solution to reduce drag and weight while maintaining longitudinal static stability.
Article
Computer Science, Interdisciplinary Applications
Suhas S. Jain, Ali Mani, Parviz Moin
JOURNAL OF COMPUTATIONAL PHYSICS
(2020)
Article
Optics
Immanuvel Paul, Maxime Bassenne, Ali Mani
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2020)
Article
Computer Science, Interdisciplinary Applications
Shahab Mirjalili, Ali Mani
Summary: A new momentum transport scheme is proposed in this study for accurately and robustly simulating high Re flows with high density ratios. This scheme achieves consistency and kinetic energy conservation, and its effectiveness is demonstrated through numerical tests.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Maxime Bassenne, Lin Fu, Ali Mani
Summary: The study introduces a novel framework to handle implicit stiffness in physical terms using TASE operators, which can address both physical and numerical stiffness. The TASE method offers unconditional stability and can solve nonlinear problems while maintaining high-order accuracy.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Engineering, Chemical
Sven Schlumpberger, Raymond B. Smith, Huanhuan Tian, Ali Mani, Martin Z. Bazant
Summary: The study expands and analyzes existing leaky membrane models for shock electrodialysis, with theoretical predictions matching experimental data and numerical simulations but failing to fully capture the transition from normal to over-limiting current.
Article
Chemistry, Multidisciplinary
Hyekyung Lee, Seoyun Sohn, Shima Alizadeh, Soonhyun Kwon, Tae Jin Kim, Seung-min Park, Hyongsok Tom Soh, Ali Mani, Sung Jae Kim
Summary: An extensive investigation into the overlimiting current (OLC) behavior through electrolytes interfaced with perm-selective membranes reveals that a network of nonuniform microchannels can effectively suppress undesirable salt crystallization. Through experimental and theoretical analysis, it is demonstrated that the sensitivity of OLC to nonuniformity can be maximized, ultimately enhancing advective transport and reducing salt accumulation. These results not only advance the fundamental understanding of OLC mechanisms but also provide valuable insights for the design of electrochemical membrane applications.
Article
Physics, Fluids & Plasmas
Ali Mani, Danah Park
Summary: The study presents a numerical procedure known as the macroscopic forcing method (MFM) to reveal differential operators acting on mean fields transported by underlying fluctuating flows, specifically the eddy diffusivity operator. The method is shown to accurately capture nonlocal mixing effects and has a cost-effective generalization for analysis of nonhomogeneous and wall-bounded flows.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Mechanics
Jeremy A. K. Horwitz, Swetava Ganguli, Sanjiva K. Lele, Ali Mani
Summary: This work establishes a procedure to accurately compute heat transfer between an Eulerian fluid and Lagrangian point-particles, by estimating the undisturbed fluid temperature to achieve thermal coupling. The authors developed a scheme to accurately estimate the undisturbed fluid temperature of point-particles exchanging thermal energy with surrounding fluid and conducted extensive verification of the correction procedure.
THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Immanuvel Paul, Ali Mani
Summary: In this study, a novel and cost-effective solution to the radiation transport equation on a Eulerian domain is proposed. By deriving an expression for the absorption coefficient, the solution achieves high accuracy and verifiability. Experimental results demonstrate that this method can handle particle clouds that violate the Beer-Bouguer law constraints and converge to the gold-standard solution after mesh refinement.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mechanics
J. A. K. Horwitz, G. Iaccarino, J. K. Eaton, A. Mani
Summary: A methodology for simulating two-way coupled particle-laden flows is outlined in this study, which accurately models the interaction between fluid and particles at low particle Reynolds numbers and can be extended to other physics like heat transfer and electromagnetism. By verifying and extending the discrete Green's function method, accurate results for particle-laden flows under different conditions can be obtained.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Chemical
Felix Stockmeier, Michael Schatz, Malte Habermann, John Linkhorst, Ali Mani, Matthias Wessling
Summary: The study introduces a new experimental method for time-resolved recording of the 3D electroconvective velocity field near a cation-exchange membrane, visualizing the spatio-temporal velocity field in 3D at multiples of the overlimiting current density. The research reveals changes in the velocity field from vortex rolls to vortex rings with increasing current density, with significant impacts on mean square velocities and temporal spectra rather than spatial spectra.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Physics, Fluids & Plasmas
Yasaman Shirian, Ali Mani
Summary: In this study, the scale-dependent eddy diffusivity characterizing scalar and momentum transport in incompressible homogeneous isotropic turbulence is computed using the recently developed macroscopic forcing method. The results show that the eddy diffusivity is constant for scales larger than the energy containing eddies, but vanishes inversely proportional to the wave number for small scales. These findings can be reasonably captured by a nonlocal eddy diffusivity operator.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Thermodynamics
Shahab Mirjalili, Suhas S. Jain, Ali Mani
Summary: This article discusses the interface transfer issue in two-phase flows involving heat/mass transfer. Two models are proposed to address the challenge of the undefined interface in phase field models, and their consistency, accuracy, and convergence are validated through numerical simulations. The results suggest that the two-scalar model is more accurate than the one-scalar model in cases with large diffusivity ratios.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Physics, Fluids & Plasmas
Omkar B. Shende, Ali Mani
Summary: This work presents algebraic closure models for advective transport and nonlinear reactions in a Reynolds-averaged Navier-Stokes context. The models are developed for a system of species subject to binary reactions and transport by advection and diffusion. The presented model forms capture the influence of reaction kinetics on the closure operators and show improved prediction of mean quantities compared to previous results.
PHYSICAL REVIEW FLUIDS
(2022)
Article
Computer Science, Interdisciplinary Applications
Shahab Mirjalili, Makrand A. Khanwale, Ali Mani
Summary: Second-order phase field models have emerged as an attractive option for capturing the advection of interfaces in two-phase flows. In this work, the energy-based surface tension model from the Cahn-Hilliard context is adopted for second-order phase field models and its performance is assessed.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)