Oran, Elaine S.Overview
Publication Timeline
Most widely held works by
Elaine S Oran
Numerical simulation of reactive flow
by Elaine S Oran
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20 editions published between 1987 and 2005 in English and held by 579 WorldCat member libraries worldwide "This book takes account of the explosive growth in computer technology and the greatly increased capacity for solving complex reactiveflow problems that have occurred since the first edition of Numerical Simulation of Reactive Flow was published in 1987. It presents algorithms useful for reactiveflow simulations, describes tradeoffs involved in their use, and gives guidance for building and using models of complex reactive flows. The text covers both new topics and significant changes in the treatment of radiation transport, coupling, grids and numerical representations, and turbulence. Chapters are arranged in three broad sections: an introductory short course on modeling and numerical simulation; advanced topics in numerical simulation of reactiveflow processes; and, finally, simulations of complex reactive flows." "This new edition is an indispensable guide to how to construct, use, and interpret numerical simulations of reactive flows. It will be welcomed by advanced undergraduate and graduate students, as well as a wide range of researchers and practitioners in engineering, physics, and chemistry."BOOK JACKET
Numerical approaches to combustion modeling
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9 editions published in 1991 in English and held by 375 WorldCat member libraries worldwide
Numerical simulations of fuel droplet flows using a lagrangian triangular mesh [final report]
by M. J Fritts
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Book
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1 edition published in 1983 in English and held by 99 WorldCat member libraries worldwide
The interactions of a flame and its selfinduced boundary layer
by James Ott
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1 edition published in 1999 in English and held by 81 WorldCat member libraries worldwide
A theory of DDT in unconfined flames
by Alexei M Khokhlov
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2 editions published in 1996 in English and held by 79 WorldCat member libraries worldwide This paper outlines a theoretical approach for predicting the onset of detonation in unconfined turbulent flames. Two basic assumptions are made (1) the gradient mechanism is the inherent mechanism that leads to DDT in unconfined conditions, and (2) the sole mechanism for preparing the gradient in induction time is by turbulent mixing and local flame quenching. The criterion for DDT is derived in terms of the onedimensional detonation wave thickness, the laminar flame speed, and the laminar flame thickness in the reactive gas. This approach gives a lowerbound criterion for DDT for conditions where shock preheating, wall effects, and interactions with obstacles are absent. Regions in parameter space where unconfined DDT can and cannot occur are determined
Deflagration to detonation transition in thermonuclear supernovae
by A. M Khokhlov
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Book
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1 edition published in 1996 in English and held by 79 WorldCat member libraries worldwide We derive the criteria for deflagration to detonation transition (DDT) in a Type Ia supernova. The theory is based on the two major assumptions: (i) detonation is triggered via the Zeldovich gradient mechanism inside a region of mixed fuel and products, (ji) the mixed region is produced by a turbulent mixing of fuel and products either inside an active deflagration front or during the global expansion and subsequent contraction of an exploding white dwarf. We determine the critical size of the mixed region required to initiate a detonation in a degenerate carbon oxygen mixture. This critical length is much larger than the width of the reaction front of a ChapmanJouguet detonation. However, at densities greater than = 5 x 10(exp6) g/cc, it is much smaller than the size of a white dwarf. We derive the critical turbulent intensity required to create the mixed region inside an active deflagration front in which a detonation can form. We conclude that the density rho sub sigma at which a detonation can form in a carbonoxygen white dwarf is low, approximately less than 2 to 5 x 109exp6) g/cc, but greater than 5 x 10(exp6) g/cc
Timedependent computational studies of premixed flames in microgravity
by G Kailasanath
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Book
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1 edition published in 1993 in English and held by 72 WorldCat member libraries worldwide
Timedependent computational studies of flames in microgravity
by Elaine S Oran
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Book
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1 edition published in 1989 in English and held by 68 WorldCat member libraries worldwide
Simulations of gas phase detonations introduction of an induction parameter model
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2 editions published in 1980 in English and held by 9 WorldCat member libraries worldwide
Detailed modelling of combustion systems
by Elaine S Oran
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Book
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2 editions published in 1981 in English and held by 7 WorldCat member libraries worldwide
A onedimensional fluxcorrected transport code for detonation calculations
by David A Jones
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Book
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2 editions published between 1990 and 1991 in English and held by 6 WorldCat member libraries worldwide The development of a onedimensional FluxCorrected Transport code to model detonation in a homogeneous medium is described. The material flow is modelled using the Euler equations, and the chemical kinetics by a twostep induction parameter model which uses a quasisteady induction time and first order Arrhenius kinetics. Two different modes off initiation are compared. Conditions necessary for a selfsustaining detonation are described and illustrated. A detailed comparison is made between the variable profiles calculated by the code and those calculated analytically using the simple ChapmanJouguet theory and selfsimilar analysis, and the overall agreement is excellent. The effect of the computational cell size on these solutions is also considered
Numerical simulation of detonation transfer between gaseous explosive layers
by David A Jones
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Book
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1 edition published in 1989 in English and held by 5 WorldCat member libraries worldwide
A theoretical study of a spin hamiltonian with biquadratic pair interactions
by Elaine S Oran
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Book
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1 edition published in 1972 in English and held by 2 WorldCat member libraries worldwide
Dynamics of an Unsteady Diffusion Flame: Effects of Heat Release and Gravity
by Janet L Ellzey
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Book
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2 editions published in 1990 in English and held by 2 WorldCat member libraries worldwide This report presents timedependent axisymmetric numerical simulations of an unsteady diffusion flame formed between a jet and a coflowing air stream. The computations include the effects of convection, molecular diffusion, thermal conduction, viscosity, gravitational forces, and chemical reactions with energy release. Previous work has shown that viscous effects are important in these flames and, therefore, all of the viscous terms in the compressible NavierStokes equations are included. In addition, the resolution is increased so that the large, vortical structures in the coflowing gas are resolved and the boundary conditions are improved so that the velocity field near the jet is more realistic. Computations with and without chemical reactions and heat release, and with and without gravity, are compared. Gravitational effects are insignificant in the nonreacting jet but in the reacting jet gravity produced the relatively lowfrequency instabilities typically associated with flame flicker. KelvinHelmholtz instabilities develop in the region between the highvelocity and lowvelocity fluid when there are no chemical reactions, but heat release dampens these instabilities to produce a mixing region which is almost steady in time
The Stability and Multiplicity of the Monotonic Lagrangian Grid
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1 edition published in 1997 in English and held by 1 WorldCat member library worldwide The Monotonic Lagrangian Grid (MLG) is a data structure in which nodes are ordered in a monotonic way such that those nodes which are close in physical space also have nearby indices in the data structure arrays. An MLG ordering for a given system of nodes, as defined by the monotonicity constraints, is not unique. For all but the smallest systems, the number of allowed orderings is extremely large with many of the possible MLG's so badly structured that they lead to poor results when used in physical calculations. A wellstructured MLG ordering is one that corresponds well to the physical ordering of the system. This paper shows that the majority of the MLG's for a given set of node locations are poorly structured, but that the small fraction which are wellstructured tend to be extremely stable against perturbations of the node positions. It is this extreme stability of the wellstructured MLG's that is responsible for both the utility of this approach in particlebased simulations and the success of stochastic grid regularization, a technique for restructuring from a poorly structured to a wellstructured MLG. The high probability of encountering a wellstructured MLG when the node dynamics is complex, even without stochastic grid regularization, is a result of this relative stability
The Interaction of HighSpeed Turbulence with Flames: Turbulent Flame Speed
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1 edition published in 2010 in English and held by 1 WorldCat member library worldwide Direct numerical simulations of the interaction of a premixed flame with subsonic, highspeed, homogeneous, isotropic, Kolmogorovtype turbulence in an unconfined system show anomalously high turbulent flame speeds, S(T) . Data from these simulations are analyzed to identify the origin of this anomaly. The simulations were performed with AthenaRFX, a massively parallel, fully compressible, highorder, dimensionally unsplit, reactiveflow code. A simplified reactiondiffusion model represents a stoichiometric H2air mixture under the assumption of the Lewis number L(e) = 1. Global properties and the internal structure of the flame were analyzed in an earlier paper, which showed that this system represents turbulent combustion in the thin reaction zone regime with the average local flame speed equal to its laminar value, S(L). This paper shows that: (1) Flamelets inside the flame brush have a complex internal structure, in which the isosurfaces of higher fuel mass fractions are folded on progressively smaller scales. (2) Global properties of the turbulent flame are best represented by the structure of the region of peak reaction rate, which defines the flame surface. (3) The observed increase of S(T) relative to S(L) exceeds the corresponding increase of the flame surface area, A(T), relative to the surface area of the planar laminar flame, on average, by 30% and occasionally by as much as 50% in the course of system evolution. This exaggerrated response of S(T) shows that Damkohler's paradigm breaks down for sufficiently highintensity turbulence, namely at Karlovitz numbers Ka ~ 20, even in the flows characterized by L(e) = 1. (4) The breakdown is the result of tight flame packing by turbulence, which causes frequent flame collisions and formation of regions of high flame curvature 1/ L, or "cusps," where L is the thermal width of the laminar flame
CHEMEQ2: A Solver for the Stiff Ordinary Differential Equations of Chemical Kinetics
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1 edition published in 2001 in English and held by 1 WorldCat member library worldwide This report describes and documents the subroutine CHEMEQ2, used to integrate stiff ordinary differential equations arising from reaction kinetics. This is a second generation improvement of CHEMEQ using a new quasisteadystate predictorcorrector method that is Astable for linear equations and secondorder accurate. A single integration method can now be used for all species, regardless of the timescales of the individual equations. Startup costs and memory requirements are low, so CHEMEQ2 is ideal for multidimensional reactingflow simulations which require the solution of a processsplit, initialvalue problem in every computational cell for every global timestep. The algorithm, its implementation, the FORTRAN code, the internal variables and the argument lists are presented, along with several test problem results
International Workshop on Mathematical Methods in Combustion Held in Como, Italy on 1822 May 1992
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1 edition published in 1992 in English and held by 1 WorldCat member library worldwide The overall objective of the Workshop was to try to improve communications and promote crossfertilizations between applied mathematicians and computational scientists, by pointing out promising directions as well as effective means of interaction. Specific objectives of the Workshop were to critically compare analytic to numerical approaches, assess potentials and limitations of both, and hopefully foster new developments in combustion. To this end, a proper mix of formal lectures, specialized presentations, informal discussions, and constructive crosscriticism was implemented
Theoretical and Computational Approach to Modeling Flame Ignition
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1 edition published in 1979 in English and held by 1 WorldCat member library worldwide In this paper, timedependent results obtained from a simplified but nonlinear analytic similarity solution and a detailed numerical simulation are used to study the relations between the fundamental processes occurring in the very early stages of flame ignition in homogeneous premixed gases. The parameters which may be varied are the composition of the mixture, the initial radius of energy deposition R sub 0, the duration of the heating TAN SUB 0, and the total energy deposited in the system E sub 0. The similarity solution plus the ignition delay times Tau sub c for the fueloxidizer mixture as a function of temperature can be used to calculate whether or not a given energy source is adequate to ignite the system. This simple procedure may then be calibrated using the timedependent NRL detailed reactive flow models. The models include the thermophysical properties of the mixture, a full chemical kinetics scheme, the nonlinear convection of selfconsistent fluid dynamics and the matrix molecular diffusion coefficients for the individual species. Results are presented for a selected mixture of H2O2N2 for two values of R sub 0 which show that a model must be constructed for a quench volume in order to complete the similarity solution calibration. (Author)
A OneDimensional TimeDependent Model for Flame Initiation, Propagation and Quenching
by K Kailasanath
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Book
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1 edition published in 1982 in English and held by 1 WorldCat member library worldwide This report describes a onedimensional, timedependent, Lagrangian numerical model developed to study the initiation, propagation and quenching of laminar flames. A number of new approaches and algorithms as well as input parameters used in the model are discussed. Calculations of initiation and minimum ignition energies in hydrogenoxygennitrogen mixtures are presented along with calculations of the burning velocity of hydrogen in air. (Author) more
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Chemical kineticsMathematical models Combustion Combustion, Theory of CombustionComputer simulation CombustionEffect of reduced gravity on CombustionResearch Computer simulation Degeneration Detonation wavesComputer simulation Electronhole droplets ExplosionsComputer simulation ExplosionsMathematical models Flame Fluid dynamicsMathematical models Gas dynamicsMathematical models Gravity Lagrangian points Laminar flow Mathematical models NavierStokes equations Shock waves Supernovae Transport theoryMathematical models Turbulence

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