27 papers · ranked by Valyu relevance
Hitesh Kishore Das, Max Grönke, Rainer Weinberger
Multiphase gas, with hot (∼ 106K) and cold (∼ 104K) gas, is ubiquitous in astrophysical media across a wide range of scales. However, simulating multiphase gas has been a long-standing challenge, due to the large separation between the size of cold gas structures and the scales at which such gas impacts the evolution…
Wayne O'Keeffe, T. P. Downes
Turbulent motion driven by the magnetorotational instability (MRI) is believed to provide an anomalous viscosity strong enough to account for observed accretion rates in protostellar accretion disks. In the first of two papers, we perform large-scale, three fluid simulations of a weakly ionised accretion disk and…
Donna Rodgers-Lee, T. P. Ray, T. P. Downes
The redistribution of angular momentum is a long standing problem in our understanding of protoplanetary disk (PPD) evolution. The magnetorotational instability (MRI) is considered a likely mechanism. We present the results of a study involving multifluid global simulations including Ohmic dissipation, ambipolar…
Marco Crialesi-Esposito, Nicolò Scapin, Andreas D. Demou, Marco Edoardo Rosti + 3 more
'Marco Edoardo Rosti' 'Paulo Costa' 'Filippo Spiga' 'Luca Brandt'] We present the Fluid Transport Accelerated Solver, FluTAS, a scalable GPU code for multiphase flows with thermal effects. The code solves the incompressible Navier-Stokes equation for two-fluid systems, with a direct FFTbased Poisson solver for the…
Thao X. D. Nguyen, Tuan V. Vu, Sepideh Razavi, Dimitrios V. Papavassiliou + 2 more
'Dimitrios V. Papavassiliou' 'Vlasis Mavrantzas' 'Doros Theodorou'] Coarse-grained modeling methods allow simulations at larger scales than molecular dynamics, making it feasible to simulate multifluid systems. It is, however, critical to use model parameters that represent the fluid properties with fidelity under both…
Carlos E. Alvarado-Rodríguez, Jaime Klapp, José M. Domínguez, Agustín Ramón Uribe Ramírez + 2 more
'Agustín Ramón Uribe Ramírez' 'J.J. Ramírez-Minguela' 'M. Gómez‐Gesteira'] Abstract. This work presents a new multiphase SPH model that includes the shifting algorithm and a variable smoothing length formalism to simulate multiphase flows with accuracy and proper interphase management. The implementation was performed…
Julian Vorspohl, Yuxing Peng, S. Berger, Dominik Krug + 1 more
A novel coupled level-set lattice Boltzmann method on adaptive Cartesian grids for simulating liquid-gas multiphase flows is presented. The approach addresses the inherent challenges of accurately modeling multiphase systems characterized by sharp interfaces and large density ratios. By employing separate solution…
T. P. Downes
It is believed that turbulence may have a significant impact on star formation and the dynamics and evolution of the molecular clouds in which this occurs. It is also known that non-ideal magnetohydrodynamic effects influence the nature of this turbulence. We present the results of a numerical study of 4-fluid MHD…
Seyed Ali Hosseini, Hesameddin Safari, Dominique Thevenin
The lattice Boltzmann method, now widely used for a variety of applications, has also been extended to model multiphase flows through different formulations. While already applied to many different configurations in low Weber and Reynolds number regimes, applications to higher Weber/Reynolds numbers or larger…
Zeren Yang, Sha Liu, Congshan Zhuo, Chengwen Zhong + 3 more
'Liangqi Zhang' 'Liming Yang'] The multiphase model based on free-energy theory has been experiencing long-term prosperity for its solid foundation and succinct implementation. To identify the main hindrance to developing a free-energy-based discrete unified gas-kinetic scheme (DUGKS), we introduced the classical…
Aaron J. Rowane, Elizabeth G. Rasmussen
Measurements of Binary Mixtures of trans -1,2-Difluoroethylene (R-1132(E)) with Difluoromethane (R-32) or 2,3,3,3-Tetrafluoropropene (R-1234yf) Authors: ['Aaron J. Rowane' 'Elizabeth G. Rasmussen'] The speed of sound of two binary mixtures containing 0.336 mole fraction trans-1,2-difluoroethylene (R-1132(E)) with…
Michel Takken, Robert Wille, Konstantinos Salonitis, Panagiotis Kyratsis
'Panagiotis Kyratsis'] The design of microfluidic devices is a cumbersome and tedious process that can be significantly improved by simulation. Methods based on Computational Fluid Dynamics (CFD) are considered state-of-the-art, but require extensive compute time-oftentimes limiting the size of microfluidic devices…
Johanna Busch, Dietmar Paschek
In a recent paper [J. Phys. Chem.B 127, 7983-7987 (2023)] , we have shown that for molecular dynamics (MD) simulations using orthorhombic periodic boundary conditions with "magic" box length ratios of $L_z/L_x=L_z/L_y=2.7933596497$, the self-diffusion coefficients $D_x$ and $D_y$ in $x$- and $y$-direction are…
Christoph Schwarzmeier, Ulrich Rüde
The accuracy of the free-surface lattice Boltzmann method (FSLBM) depends significantly on the boundary condition employed at the free interface. Ideally, the chosen boundary condition balances the forces exerted by the liquid and gas pressure. Different variants of the same boundary condition are possible, depending…
Wenqiang Guo, Mikhail Sheremet, Tianbai Xiao, Yuan Hu + 1 more
In this work, the Simpson method is proposed to calculate the interface flux of a discrete unified gas kinetic scheme (DUGKS) according to the distribution function at the node and the midpoint of the interface, which is noted by Simpson-DUGKS. Moreover, the optimized DUGKS and Simpson-DUGKS considering the force term…
Hafiz Muhammad Musharaf, Uditha Roshan, Amith Mudugamuwa, Quang Thang Trinh + 3 more
'Quang Thang Trinh' 'Jun Zhang' 'Nam-Trung Nguyen' 'S. Kokou Dadzie'] Micro elastofluidics is a transformative branch of microfluidics, leveraging the fluid-structure interaction (FSI) at the microscale to enhance the functionality and efficiency of various microdevices. This review paper elucidates the critical role…
Authors not listed
A multi-fidelity Monte Carlo framework for molecular dynamics simulations of the diffusion coefficient of liquid water is presented. The model hierarchy is constructed based on the size of the simulation box, taking advantage of the well-known size effects that simulations of the diffusion coefficient suffer from.…
Kieu Trinh Do, David J.N.-P. Rasp, Gabi Kastenmüller, Karsten Suhre + 1 more
Metabolomics is an established tool to gain insights into (patho)physiological outcomes. Associations of metabolism with such outcomes are expected to span functional modules, which are defined as sets of correlating metabolites that are coordinately regulated. Moreover, these associations occur at different scales…
Martin Kutscherauer, Scott Anderson, Sebastian Böcklein, Gerhard Mestl + 2 more
Modeling catalytic fixed bed reactors with a small tube-to-particle diameter ratio requires a detailed description of the interactions between fluid flow, intra-particle transport, and the chemical reaction(s) within the catalyst. Particle-resolved computational fluid dynamics (PRCFD) simulations are the most promising…
Rajat Mishra, Devashree Jahagirdar, Saumya Jaiswal, Amit Arora + 1 more
A coupled CFD-DEM framework was developed to investigate red blood cell (RBC) transport and cellular adhesion in constricted microchannels, with a primary objective of reducing computational cost while preserving physiological accuracy. Initially, numerical softening factors were implemented, allowing greater overlap…
Rajat Mishra, Saumya Jaiswal, Amit Arora, Abhijit Majumder
A coupled CFD-DEM framework was developed to investigate red blood cell (RBC) transport and cellular adhesion in constricted microchannels, with a primary objective of reducing computational cost while preserving physiological accuracy. Initially, numerical softening factors were implemented, allowing greater overlap…
Avinash Vaidheeswaran, Cheng Li, Huda Ashfaq, Xiongjun Wu + 2 more
Bubbling fluidization experiments were performed in three cylindrical columns having internal diameters of 2.5, 4 and 6 inches. Glass particles having a sauter mean diameter of 332 microns were used, and the operating conditions were held constant in all the units. Statistics of differential pressure and interface…
Authors not listed
This study introduces an implementation of multiple Gaussian filters within the Hamiltonian hybrid particle-field (HhPF) theory, aimed at capturing phase coexistence phenomena in mesoscopic molecular simulations. By employing a linear combination of two Gaussians, we demonstrate that HhPF can generate potentials with…
Fergus R. Cooper, Ruth E. Baker, Alexander G. Fletcher
Mathematical modelling provides a useful framework within which to investigate the organization of biological tissues. With advances in experimental biology leading to increasingly detailed descriptions of cellular behaviour, models that consider cells as individual objects are becoming a common tool to study how…
Tobias Seidel, Lena-Marie Ränger, Thomas Grützner, Michael Bortz
In this work we present a new approach that we use to simulate and optimize multiple dividing wall columns at the same time. Instead of considering all model equations as constraints and all process variables as optimization variables in a large and highly nonlinear optimization problem we only incorporate a subset of…
J. Scott Malloy, Sreeparna Majee, Akshita Sahni, Ricardo Roopnarinesingh + 3 more
Computational analysis of physiological and biomedical systems necessitate efficient geometry representations for high fidelity model predictions, including patient or device specificity. Particle-based Lagrangian computational approaches comprise a valuable approach to gain insights from quantitative velocity and…
Hanne S. Antila, Sneha Dixit, Batuhan Kav, Jesper J. Madsen + 2 more
Owing to the increase of available computational capabilities and the potential for providing more accurate description, polarizable molecular dynamics force fields are gaining popularity in modelling biomolecular systems. It is, however, crucial to evaluate how much precision is truly gained with the increased cost…