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Showing 1 to 19 of 19 for “"moment closure"”.
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Computations of Turbulent Premixed Flames Using Conditional Moment Closure
… for predicting pollutants is the conditional moment closure (CMC), which is suitable to predict pollutants with slow time scales. Despite the fact that CMC has been successfully applied to various non-premixed combustion systems, its application to premixed flames is not fully tested and …
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Modelling of Spray Combustion with Doubly Conditional Moment Closure
… presents the development of Doubly Conditional Moment Closure (DCMC) for the modelling of turbulent spray combustion. This modelling approach allows us to consider the effects of finite-rate chemistry and spray evaporation on the flame. Using a parametrisation of the flame structure, based on …
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A Basic Three-Dimensional Turbulent Boundary Layer Experiment To Test Second-Moment Closure Models
In this work, a three-dimensional turbulent boundary layer experiment was set up with alternating stream-wise and span-wise pressure gradients. The pressure gradients are generated as a result of the test section wavy side wall shape. Each side had six sine waves with a trough to peak magnitude to …
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Development of a 20-moment Polydisperse and Polykinetic Spray Model Coupled With a Surface Density Approach for the Modelling of the Dense and Disperse Liquid Spray Regimes
… jet/sheet in the dense spray regime while the 20-moment Anisotropic Gaussian (AG) moment closure modelling approach is used for the disperse spray regime. Current state-of-art primary atomization modelling approaches used to obtain the droplet probability density function (PDF) are either …
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Inertial manifolds in biological systems
… number of differential equations for the moments are approximated using a Moment Closure technique, that is expressing moments of order higher than N as a function of the first moments, generally using the function valid for the normal distribution. The example shows exceptional …
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Existence of smooth shock profiles for hyperbolic systems with relaxation
… We apply our results to exponentially based moment closure systems.
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I. Kinetic Modeling of Surface Reactions II. Computational Design of Organic Semiconductors
In Part I of this thesis, we propose moment closure methods to simulate the chemical kinetics of surface reactions. For systems with static disorder in the rate constants and short-range correlation in the densities of reactants, we propose the half heterogeneous pair approximation (HHPA). …
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Modelling of turbulent swirling flows
… are presented along with the LRR and SSG second-moment closure models for isothermal and variable density flows. The effect of anisotropy in the Reynolds stress dissipation rate tensor is accounted for by the inclusion of an algebraic model for the dissipation anistropy tensor dependent 0n the …
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Accounting for unpredictable spatial variability in plankton ecosystem models
… dynamics can be serious, and that ‘spatial moment closure’ and<br/>similar statistical modelling techniques may be profitably applied to account for them.
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Using semidefinite programming to bound distributions in chemical engineering systems
… a rigorous solution to the long-standing "moment closure problem" arising in stochastic chemical kinetics. Moreover, it provides a means of analyzing of stochastic chemical kinetic systems which cannot be effectively analyzed using existing methods. The bounding method does have some …
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Anisotropic Turbulence Models for Wakes in an Active Ocean Environment
A set of second-moment closure turbulence models are implemented for the study of wake evolution in an oceanic environment. The effects of density stratification are considered, and the models are validated against laboratory experiments mimicking the stratified ocean environment, and against …
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Development of a Multifluid Magnetohydrodynamic Model for Anisotropic, Partially Ionized Plasmas
… models are described that both make use of a 10-moment or Gaussian anisotropic moment closure of the Boltzmann equation. The moment equations for each plasma species are fully coupled to the Maxwell's equations which govern electromagnetic wave propagation within the plasma and a …
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Simulations of turbulent swirl combustors
… to an advanced combustion model: the Conditional Moment Closure (CMC). Numerical predictions have been systematically compared and validated with detailed experimental datasets. In order to analyze further the physics underlying the large numerical datasets, Proper Orthogonal Decomposition (POD) …
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An Approximation for the Twenty-One-Moment Maximum-Entropy Model of Rarefied Gas Dynamics
The use of moment-closure methods to predict continuum and moderately rarefied flow offers many modelling and numerical advantages over traditional methods. The maximum-entropy family of moment closures offers models described by hyperbolic systems of balance laws. In particular, the twenty-one …
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Autoignition in turbulent two-phase flows
… droplet related effects within the Conditional Moment Closure (CMC) method for turbulent non-premixed combustion. The dissertation can be split in four different sections, with the content of each being summarized below. The first part of the dissertation introduces the equations that govern the …
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Extinction in turbulent swirling non-premixed flames
… Simulation (LES) and sub-grid scale Conditional Moment Closure (CMC) model. The first part of this thesis describes the derivations of the three dimensional conservative CMC governing equations and their finite volume discretization for unstructured mesh. The parallel performance of the newly …
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Predicting Soot Emissions with Advanced Turbulent Reacting Flow Modelling
… soot model coupled with the Conditional Moment Closure (CMC) turbulent combustion model and Large Eddy Simulation (LES). This modelling approach allows for an elaborate description of the unsteady reacting field and explicitly accounts for transport, history and finite-rate chemistry …
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Simulating Extinction and Blow-off in Kerosene Swirl Spray Flames
… Eddy Simulations (LES) with the Conditional Moment Closure (CMC) turbulence-combustion model are used, as this methodology has shown good results in simulating extinction and blow-off in both gaseous and spray flames in a lab-scale bluff body swirl spray flame configuration. The jet fuels …