Conditional Moment Closure for Spray Combustion and Ignition

Conditional Moment Closure for Spray Combustion and Ignition PDF Author: Peter Schroll
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Conditional Moment Closure for Spray Combustion and Ignition

Conditional Moment Closure for Spray Combustion and Ignition PDF Author: Peter Schroll
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Numerical Investigation of Turbulent Spray Combustion with Conditional Moment Closure

Numerical Investigation of Turbulent Spray Combustion with Conditional Moment Closure PDF Author: Yuri Martin Wright
Publisher:
ISBN:
Category :
Languages : en
Pages : 135

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Turbulent Combustion Modeling

Turbulent Combustion Modeling PDF Author: Tarek Echekki
Publisher: Springer Science & Business Media
ISBN: 9400704127
Category : Technology & Engineering
Languages : en
Pages : 496

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Book Description
Turbulent combustion sits at the interface of two important nonlinear, multiscale phenomena: chemistry and turbulence. Its study is extremely timely in view of the need to develop new combustion technologies in order to address challenges associated with climate change, energy source uncertainty, and air pollution. Despite the fact that modeling of turbulent combustion is a subject that has been researched for a number of years, its complexity implies that key issues are still eluding, and a theoretical description that is accurate enough to make turbulent combustion models rigorous and quantitative for industrial use is still lacking. In this book, prominent experts review most of the available approaches in modeling turbulent combustion, with particular focus on the exploding increase in computational resources that has allowed the simulation of increasingly detailed phenomena. The relevant algorithms are presented, the theoretical methods are explained, and various application examples are given. The book is intended for a relatively broad audience, including seasoned researchers and graduate students in engineering, applied mathematics and computational science, engine designers and computational fluid dynamics (CFD) practitioners, scientists at funding agencies, and anyone wishing to understand the state-of-the-art and the future directions of this scientifically challenging and practically important field.

Conditional Moment Closure for Turbulent Combustion

Conditional Moment Closure for Turbulent Combustion PDF Author: A. Yu Klimenko
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages :

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Conditional Moment Closure for Non-premixed Turbulent Combustion

Conditional Moment Closure for Non-premixed Turbulent Combustion PDF Author: Ik Soo Kim
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Development of the Conditional Moment Closure Method for Modelling Turbulent Combustion

Development of the Conditional Moment Closure Method for Modelling Turbulent Combustion PDF Author: Nigel Stuart Allen Smith
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages : 470

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Modeling and Simulation of Turbulent Combustion

Modeling and Simulation of Turbulent Combustion PDF Author: Santanu De
Publisher: Springer
ISBN: 9811074100
Category : Science
Languages : en
Pages : 663

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Book Description
This book presents a comprehensive review of state-of-the-art models for turbulent combustion, with special emphasis on the theory, development and applications of combustion models in practical combustion systems. It simplifies the complex multi-scale and nonlinear interaction between chemistry and turbulence to allow a broader audience to understand the modeling and numerical simulations of turbulent combustion, which remains at the forefront of research due to its industrial relevance. Further, the book provides a holistic view by covering a diverse range of basic and advanced topics—from the fundamentals of turbulence–chemistry interactions, role of high-performance computing in combustion simulations, and optimization and reduction techniques for chemical kinetics, to state-of-the-art modeling strategies for turbulent premixed and nonpremixed combustion and their applications in engineering contexts.

Experiments and Numerical Simulations of Turbulent Combustion of Diluted Sprays

Experiments and Numerical Simulations of Turbulent Combustion of Diluted Sprays PDF Author: Bart Merci
Publisher: Springer Science & Business Media
ISBN: 3319046780
Category : Technology & Engineering
Languages : en
Pages : 167

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Book Description
This book reflects the results of the 2nd and 3rd International Workshops on Turbulent Spray Combustion. The focus is on progress in experiments and numerical simulations for two-phase flows, with emphasis on spray combustion. Knowledge of the dominant phenomena and their interactions allows development of predictive models and their use in combustor and gas turbine design. Experts and young researchers present the state-of-the-art results, report on the latest developments and exchange ideas in the areas of experiments, modelling and simulation of reactive multiphase flows. The first chapter reflects on flame structure, auto-ignition and atomization with reference to well-characterized burners, to be implemented by modellers with relative ease. The second chapter presents an overview of first simulation results on target test cases, developed at the occasion of the 1st International Workshop on Turbulent Spray Combustion. In the third chapter, evaporation rate modelling aspects are covered, while the fourth chapter deals with evaporation effects in the context of flamelet models. In chapter five, LES simulation results are discussed for variable fuel and mass loading. The final chapter discusses PDF modelling of turbulent spray combustion. In short, the contributions in this book are highly valuable for the research community in this field, providing in-depth insight into some of the many aspects of dilute turbulent spray combustion.

Autoignition in Turbulent Two-phase Flows

Autoignition in Turbulent Two-phase Flows PDF Author: Giulio Borghesi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This dissertation deals with the numerical investigation of the physics of sprays autoigniting at diesel engine conditions using Direct Numerical Simulations (DNS), and with the modelling of 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 temporal and spatial evolution of a turbulent reacting flow, and provides an extensive review of the CMC method for both single and two-phase flows. The problem of modelling droplet related effects in the CMC transport equations is discussed in detail, and physically-sound models for the unclosed terms that appear in these equations and that are affected by the droplet presence are derived. The second part of the dissertation deals with the application of the CMC method to the numerical simulation of several n-heptane sprays igniting at conditions relevant to diesel engine combustion. Droplet-related terms in the CMC equations were closed with the models developed in the first part of the dissertation. For all conditions investigated, CMC could correctly capture the ignition, propagation and anchoring phases of the spray flame. Inclusion of droplet terms in the CMC equations had little influence on the numerical predictions, in line with the findings of other authors. The third part of the dissertation presents a DNS study on the autoignition of n-heptane sprays at high pressure / low temperature conditions. The analysis revealed that spray ignition occurs first in well-mixed locations with a specific value of the mixture fraction. Changes in the operating conditions (initial turbulence intensity of the background gas, global equivalence ratio in the spray region, initial droplet size distribution) affected spray ignition through changes in the mixture formation process. For each spray, a characteristic ignition delay time and a characteristic droplet evaporation time could be defined. The ratio between these time scales was suggested as a key parameter for controlling the ignition delay of the spray. The last part of the dissertation exploits the DNS simulations to perform an a priori analysis of the applicability of the CMC method to autoigniting sprays. The study revealed that standard models for the mixing quantities used in CMC provide poor approximations in two-phase flows, and are partially responsible for the poor prediction of the ignition delay time. It was also observed that first-order closure of the chemical source terms performs poorly during the onset of ignition, suggesting that second-order closures may be more appropriate for studying spray autoignition problems. The contribution of the work presented in this dissertation is to provides a detailed insight into the physics of spray autoignition at diesel engine conditions, to propose and derive original methods for incorporating droplet evaporation effects within CMC in a physically-sound manner, and to assess the applicability and shortcomings of the CMC method to autoigniting sprays.

An Introduction to Turbulent Reacting Flows

An Introduction to Turbulent Reacting Flows PDF Author: R. S. Cant
Publisher: Imperial College Press
ISBN: 1860947786
Category : Science
Languages : en
Pages : 192

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Book Description
Provides physical intuition and key entries to the body of literature. This book includes historical perspective of the theories.