Full Record

New Search | Similar Records

Title Novel Treatments for Multi-phase Flow Prediction Inspired By Kinetic Theory
Publication Date
Date Accessioned
University/Publisher University of Ottawa
Abstract This study entails an investigation of a novel moment closure, originally constructed for rarefied-gas prediction, to the modelling of inert, dilute, disperse, particle flows. Such flows are important in many engineering situations. As one example, in internal-combustion engines, fuel is often injected as a spray of tiny droplets and, during combustion, a cloud of tiny soot particles can be formed. These particle phases are often difficult to model, especially when particles display a range of velocities at each location in space. Lagrangian methods are often too costly and many Eulerian field-based methods suffer from model deficiencies and mathematical artifacts. Often, Eulerian formulations assume that all particles at a location and time have the same velocity. This assumption leads to nonphysical results, including an inability to predict particle paths crossing and a limited number of boundary conditions that can be applied. The typical multi-phase situation of many particles is, in many ways, similar to that of a gas compressed of a huge number of atoms or molecules. It is therefore expected that powerful techniques from the kinetic theory of gases could be applied. This work explores the advantages of using a modern fourteen-moment model, originally derived for rarefied gases, to predict multi-phase flows. Details regarding the derivation, the mathematical structure, and physical behaviour of the resulting model are explained. Finally, a numerical implementation is presented and results for several flow problems that are designed to demonstrate the fundamental behaviour of the models are presented. Comparisons are made with other classical models.
Subjects/Keywords Multi-phase Flow; Kinetic Theory
Language en
Country of Publication ca
Record ID handle:10393/34924
Repository ottawa
Date Indexed 2018-01-03
Issued Date 2016-01-01 00:00:00

Sample Search Hits | Sample Images | Cited Works

phase flow occurring in the engine is necessary. Multi-phase flows are omnipresent in numerous practical engineering situations. They are defined as the concurrent flow of materials with diverse states or phases (i.e., gas, solid, or liquid)…

…models Continuous distribution models Euler Sachdev Gaussian 14 Moment Figure 1.1: Hierarchy of models for multi-phase flow prediction 2 DQMOM to model multi-phase flow. We start with the Lagrangian treatment. In this treatment, we track the…

…solutions using a direct particle simulation. Previous studies have had some success in applying techniques from kinetic theory to multi-phase flow prediction. One technique allows particles at a location to have one of a set of possible velocities. This can…

…compressible Euler equations to the particle 4 phase. This technique is commonly used and available in many multi-phase flow solvers. Another model, originally derived by Levermore and Morokoff [2, 1, 18], admits 10 equations. The 10-moment…

…to be bi-model. It is expected that this will greatly improve the accuracy of the predictions for multi-phase flow. Up to now, this model has only been applied to pure gas flow. This work represents its first application to multi-phase flow prediction…

…discussed. In Chapter 4, we review the new fourteen-moment model [21] that was proposed for gas flow prediction and show how it is modified to model multi-phase flow. In Chapter 5, a numerical method for the solution of the resulting governing…

…models. 7 Chapter 2 Overview of Multi-Phase Flows and Gaskinetic Theory 2.1 Multi-Phase Flow The behaviours of multi-phase gas-particle flows can be characterized through the definition of the Stokes number, St, for a particle in a background flow

…particle phase and the background phase. For Stokes flow, it can be expressed 8 Table 2.1: Definition of several multi-phase flow regimes St 1 Particle velocity is nearly the same as the fluid velocity St ≈ 1 Significant velocity difference are present…