On the structure of gaseous confined laminar spray diffusion flames/numerical investigation

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National Aeronautics and Space Administration, For sale by the National Technical Information Service, distributor , [Washington, DC, Springfield, Va
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StatementM.A. Mawid, D.L. Bulzan, and S.K. Aggarwal.
SeriesNASA technical memorandum -- 106039., ICOMP -- no. 93-3., NASA technical memorandum -- 106039., ICOMP -- no. 93-3.
ContributionsBulzan, D. L., Agrawal, S. K., United States. National Aeronautics and Space Administration.
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Pagination1 v.
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Open LibraryOL14693093M

The structure and characteristics of gaseous confined laminar diffusion flames are investigated by numerically solving the time-dependent two-dimensional. Get this from a library. On the structure of gaseous confined laminar spray diffusion flames/numerical investigation.

[M A Mawid; Daniel L Bulzan; S K Aggarwal; United States. National Aeronautics and Space Administration.]. The structure of confined laminar spray diffusion flames is investigated numerically by solving the gas-phase conservation equations for mass species, continuity, momentum, and energy and the liquid-phase equations for droplet position, velocity, size, and temperature.

A one-step global reaction scheme along with six equilibrium reactions are employed to model the flame : M. Mawid, D.

Bulzan, S. Aggarwal. NASA Technical Memorandum _8 ICOMP p27 Structure of Confined Laminar Spray Diffusion f Flames/Numerical investigation M.A. Mawid Institute for. For a general description of the diffusion flames see, for example, the review papers by Barr (13) and Wohl and Shipmann (14), where data and bibliography on the subject can be found.

We aim in this work to show the effects of finite chemical reaction rates on the structure of laminar diffusion flames.

In this work, a combined theoretical and numerical study of the impact of spray evaporation on the structure of laminar spray flames is presented. Numerical simulations of an axisymmetric laminar mono-disperse ethanol/air counterflow spray flame are performed in order to evaluate the influence of spray evaporation on flame characteristics.

Laminar diffusion flames over a porous plate, through which a gaseous fuel is injected, have long been used to simulate the gas phase part of condensed fuel burning experimentally, analytically, and numerically [Emmons, ; de Ris.

A numerical simulation of an axisymmetric confined diffusion flame formed between a H2 N2 jet and coflowing air at 30 cm/s is presented. For the initial computations, the restrictions of the Burke. Study of a Co-flow Laminar CH 4/Air Diffusion Flames [7, 31]. A numerical simulation of an axisymmetric confined diffusion flame formed between a H2-N2 jet and co-flowing air, each at a velocity of 30 cm/s, were presented by Ellzey et al.

[8] and Li et al. [9] investigated a highly over-ventilated laminar co-flow diffusion flame in. The formation/combustion of soot in laminar and simple turbulent jet diffusion flames has been studied by many researchers Brooks and Moss9 presented results of numerical modeling of piloted axisymmetric turbulent methane-air simple jet (without swirl) flames.

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Laminar Diffusion Flames: Diffusion Flamelet Theory a gaseous fuel. The combustion zones in a diffusion flame are best described by an asymptotic expansion for very fast chemistry Flamelet Structure of a Diffusion Flame The equation for the mixture fraction.

A qualitative discussion of micro-slot flame structure is also presented. Issue Section: Combustion and Reactive Flows. Experimental and Numerical Investigation of Confined Laminar Diffusion Flames,” Influence of Gas Diluents on the Temperature of a Laminar Coflowing Jet Diffusion Flame in a Honeycomb Gaseous Burner.

Highlights Structure and reaction zones of hydrogen–methane diffusion flames are investigated. Lab-scale experiments and numerical simulations with C2 chemistry have been done. Hydrogen addition to methane enhances the reaction rate; flame extents are decreased. Methane attack by H radical is more pronounced than that of OH radical.

For hydrogen, its attack by H radical is most. Experimental and Numerical Investigation of Confined Laminar Diffusion Flames,” An Investigation of Acetylene/Argon Gas Additives to Natural Gas on the Laminar Diffusion Flame Characteristics for a Honeycomb Gaseous Burner. IMECE Structure of Propylene Turbulent Diffusion Flames in Cross-Flow Near Smoke Point.

Propagation of weakly stretched spherical flames in partially pre-vaporized fuel sprays is theoretically investigated in this work.

A general theory is developed to describe flame propagation speed. Sivathanu YR, Gore JP () Effects of gas-band radiation on soot kinetics in laminar methane/air diffusion flames. Combust Flame – CrossRef Google Scholar Smooke MD, McEnally CS, Pfefferle LD, Hall RJ, Colket MB () Computational and experimental study of soot formation in a coflow, laminar diffusion Flame.

F.A. Williams, in Encyclopedia of Physical Science and Technology (Third Edition), VII.A Experimental Configurations of Diffusion Flames.

In diffusion flames, two types of feed streams can be identified; fuel streams and oxidizer streams.A common configuration is a fuel jet issuing into a quiescent oxidizing gas or into a co-flowing oxidizer stream in a duct, as studied by Burke and.

The present investigation is intended to contribute towards the development of a consistent asymptotic description of the diffusion flame in hydrogen-oxygen systems. Such a description can be useful in studying propagation of triple flames in nonuniform mixtures, stability of diffusion flames and nonpremixed turbulent combustion in.

configuration. This investigation focuses on the structure of coflow laminar spray diffusion flames and how it is affected by a 3-fold change in pressure.

Previous numerical work on these flows highlighted the presence of relatively large droplets that pene-trate the flame [7].

However, dependingonthetime. The effects of pressure on soot formation and the structure of the temperature field were studied in co-flow methane-air laminar diffusion flames over a wide pressure range, from atmospheric to 6 MPa (60 atm) in a high-pressure combustion chamber.

A plasma injector is designed to improve the flame stabilization of a typical coaxial injector. Based on the plasma injector experimental system, the effects of an ac dielectric barrier discharge generated plasma on a CH 4 / air inverse diffusion flame are investigated.

The electrical characteristics, discharge images, plasma species, thermal effect, gas dynamic effect, flame shape. Lift-off of jet diffusion flame in sub-atmospheric pressures: An experimental investigation and interpretation based on laminar flame speed Combustion and Flame, Vol.

No. 4 Modelling of turbulent lifted jet flames using flamelets: a priori assessment and a posteriori validation. () The importance of time-dependent flame structures in stretched laminar flamelet models for turbulent jet diffusion flames. Symposium (International) on Combustion() Structure of Laminar Opposed-flow Diffusion Flames With CO/H 2 /N 2 Fuel.

This review uses as a vehicular example the jet-flame configuration to examine some phenomena that emerge in nonpremixed gaseous combustion as a result of the interaction between the temperature-sensitive chemical reaction, typical of combustion, and the convective and diffusive transport.

These include diffusion-controlled flames, edge flames and their role in flame attachment, triple flames.

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investigating methane diffusion flame structure for different oxygen percent, they didn’t study the effect of preheating reactants stream. Juddoo et al. [3] reported an enhanced maximumtem-perature and combustion products mass fraction due to decreased nitrogen level in mixture on laminar counterflow diffusion flames.

Moreover, Ghosal et al. CiteScore: ℹ CiteScore: CiteScore measures the average citations received per peer-reviewed document published in this title.

CiteScore values are based on citation counts in a range of four years (e.g. ) to peer-reviewed documents (articles, reviews, conference papers, data papers and book chapters) published in the same four calendar years, divided by the number of.

Chen, W. & Gomez, A. Dilute laminar spray diffusion flames near the transition from group combustion to individual droplet burning. Combust. Flame– In combustion, a diffusion flame is a flame in which the oxidizer and fuel are separated before burning.

Contrary to its name, a diffusion flame involves both diffusion and convection processes. The name diffusion flame was first suggested by S.P. Burke and T.E.W. Schumann into differentiate from premixed flame where fuel and oxidizer are premixed prior to burning.

Grosch, C. & Jackson, T. Ignition and structure of a laminar diffusion flame in a compressible mixing layer with finite rate chemistry.

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Phys. Fluids 3, – «Laminar counterflow spray diffusion flames: a comparison between experimental results and complex chemistry calculations» Combustion and Flame 95 Darabiha, N. and Candel, S. () «The influence of the temperature on extinction and ignition limits of strained Hydrogen-Air diffusion flames» Combust.

Numerical investigation on effects of fuel tube diameter and co-flow velocity in a methane/air non-premixed flame. Entropy Generation in a Confined Laminar Diffusion Flame.

Combustion Science and Technology(1) Spray Diffusion Flames .A numerical investigation of the interaction between a spray flame and an acoustic forcing of the velocity field is presented in this paper. The test-case which is the focus of this work is a non-confined flame 1,2 burning at atmospheric pressure and therefore the velocity fluctuations play a key role.

Acoustic waves will eventually affect the rate of combustion, and the oscillating.Caption: Visualizations and direct numerical simulations of a methane jet diffusion flame for Re = 2, (from Ann. Rev. Fluid Mech., 47 –, ). Fuel is almost always injected into a combustion chamber as a liquid or gaseous jet, so there exists a clear interest in investigating the structure and dynamics of free and confined jets.