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Showing 1 to 20 of 32 for “"Multi-fluid"”.
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Multi-fluid Plasma Modelling
… than the bulk of the plasma. Current plasma fluid treatments assume that the velocity distribution of each particle species is described by a Maxwell-Boltzmann distribution function, and so may not be accurate for plasmas with a significant energetic component. A new method of modelling …
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Multi-fluid Plasma Modelling
… than the bulk of the plasma. Current plasma fluid treatments assume that the velocity distribution of each particle species is described by a Maxwell-Boltzmann distribution function, and so may not be accurate for plasmas with a significant energetic component. A new method of modelling …
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A Runge Kutta Discontinuous Galerkin-Direct Ghost Fluid (RKDG-DGF) Method to Near-field Early-time Underwater Explosion (UNDEX) Simulations
… compressible, inviscid and adiabatic flow, the fluid flow is governed by a set of Euler fluid equations. In practical simulations, we often encounter computational difficulties that include large displacements, shocks, multi-fluid flows with cavitation, spurious waves reflecting from boundaries …
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Covariant perturbations in f (R) - gravity of multi-component fluid cosmologies
… of matter and curvature fluctuations for a multi-fluid cosmological medium. We then specialize to a radiation-dust fluid described by barotropic equations of state. We apply the perturbation equations around a background solution of Rⁿ gravity and look at exact solutions for scales much …
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Covariant thermodynamics & relativity
… of thermal disturbances in a dissipative fluid. Although this problem is not new, its best known solution - the Israel and Stewart second order expansion - has an effective, rather than fundamental, character. The present work builds on the multi-fluid variational approach to relativistic …
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Effects of ionospheric oxygen on magnetospheric structure and dynamics
… behavior and effects of outflowing oxygen in a multi-fluid MHD model by determining (1) how O + outflow from different regions of the ionosphere contributes to plasma sheet populations and (2) the effect of these oxygen populations on convection and global magnetospheric structure. I implement …
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Computations of bubble dynamics with heat transfer
… is to develop a numerical tool to simulate multi-fluid flow problems and assess its suitability to study the enhancement effect of an ellipsoidal air bubble on heat transfer from a heated flat plate immersed in water, and the resulting flow patterns. The Volume-of-Fluid (VOF) method is …
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A one dimensional hydrodynamic simulation of colliding quasi neutral plasma systems
… and is described. The model is based on a multi-fluid theory due to P W Rambo and J Denavit [J. Comput. Phys. 98 (1992) 317] and uses a flux-corrected transport algorithm with an Eulerian grid in order to solve the three Euler equations for hydrodynamic flow. It includes source terms …
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Evaluation Of Nozzle Geometry On High Pressure Gasoline Direct Injection Spray Atomization
… The study was conducted with the aid of multi-fluid Volume-of-Fluid, Large-Eddy-Simulation, VOF-LES, method. Alternative nozzle geometries, that are the subject of current interest including varying nozzle hole length to diameter ratio, counter-bore presence and nozzle-hole skew-angle …
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Grobstruktursimulation der Biomassevergasung in einer Wirbelschicht am Beispiel von Holz
… Wechselwirkungen aus chemischen und fluiddynamischen Vorgängen zu ziehen. Die Modellierung der Gasphase berücksichtigt die Bilanzen der Dichte, der Partialdichten, des Impulses und der Gesamtenthalpie. Die turbulenten Anteile der Strömung werden mit Hilfe eines Grobstrukturansatzes …
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Modeling of fluids and waves with analytics and numerics
… an important role in experimental work such as multimaterial fiber drawing and multilayer particle fabrication. Motivated by complex multi-fluid geometries currently being explored in these applications, we theoretically and computationally studied capillary instabilities in concentric …
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A Hybrid Framework of CFD Numerical Methods and its Application to the Simulation of Underwater Explosions
… sequentially in an UNDEX scenario in both the fluid and structural domains and these events happen over a wide range of time and spatial scales. Because of the complexity of the physics involved, it is a common practice to separate the description of UNDEX into early-time and late-time, and …
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Lattice Boltzmann simulations of multiphase flows
… Method (LBM) for the purpose of simulating multiphase flows relevant to Air Conditioning and Refrigeration Center (ACRC) applications. Other methodologies have been used to simulate multiphase flow including finite volume based Navier-Stokes solvers. These methods have found reasonable …
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Numerical Analysis of Multiphase Flow in Bubble Columns and Applications for Microbial Fuel Cells
Computational fluid dynamics (CFD) modeling was used to predict the hydrodynamics of a column reactor. Bubble columns have applications across many engineering disciplines and improved modeling techniques help to increase the accuracy of numerical predictions. An Eulerian-Eulerian multi-fluid model …
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Fluid and gas models in FLRW and almost FLRW universes
… been modeled in the covariant sense, in terms of fluid models and perturbations thereof, leading to Gauge Invariant Covariant (GIC) perturbations of these fluid models. It is well known that kinetic theory provides a physically sound and consistent description of the matter and radiation in the …
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A Computational Study of the Hydrodynamics of Gas-Solid Fluidized Beds
Computational fluid dynamics (CFD) modeling was used to predict the gas-solid hydrodynamics of fluidized beds. An Eulerian-Eulerian multi-fluid model and granular kinetic theory were used to simulate fluidization and to capture the complex physics associated therewith. The commercial code ANSYS …
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Nonlinear Acoustic Waves Generated by Surface Disturbances and Their Effect on Lower Thermospheric Composition
… and less computationally expensive than a true multi-fluid model, yet captures the important physical transition between molecular and atomic gases in the lower thermosphere. Models with time-dependent composition and properties have been shown to outperform commonly used models with fixed …
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Computational fluid dynamics modelling of multi-phase flow transition in presence of solid particles.
Multi-phase flow is the type of flow common in the oil and gas industry, as oil reservoirs contain mixtures of oil, gas and water with sand particles from sandstone reservoirs. Accurate design of oil and gas production equipment greatly depends on detailed understanding of this flow phenomena. …
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A study of relativistic fluids with applications to cosmology: A variational approach
This thesis examines relativistic fluids. We have used the variational approach to develop tools for studying the dynamics of relativistic fluids to apply this to cosmological modelling. Studies like these go beyond the standard model in cosmology. Researchers believe that such extensions to the …
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Simulation methods for polydisperse, multiphase flows using moment methods
<p>While the ability to solve for multiphase flows that contain of a distribution of properties is crucial to the accurate prediction of physical system, there is currently a lack of numerical solution methods to solve for these types of flows. In this work, three new numerical procedures are …
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