Results 131 to 140 of about 1,884 (175)

Pressures and their venting in spherically expanding flames

Combustion and Flame, 1977
Abstract The Paper gives an analysis of how pressure increases with the increasing radius of a flame in a spherical vessel where the flame is ignited at its centre and propagates symmetrically outwards to the wall. The major assumptions on which the analysis is based: adiabatic compression of the contents of the vessel, the absence of significant ...
V.M. Morton, M.A. Nettleton
openaire   +1 more source

On transition to cellularity in expanding spherical flames

Journal of Fluid Mechanics, 2007
The instant of transition to cellularity of centrally ignited, outwardly propagating spherical flames in a reactive environment of fuelx–oxidizer mixture, at atmospheric and elevated pressures, was experimentally determined using high-speed schlieren imaging and subsequently interpreted on the basis of hydrodynamic and diffusional–thermal instabilities.
G. JOMAAS, C. K. LAW, J. K. BECHTOLD
openaire   +1 more source

An experimental study of laminar ammonia/methane/air premixed flames using expanding spherical flames

Fuel, 2021
Abstract The fundamental flame properties of ammonia/methane/air mixtures were experimentally investigated using expending spherical flames in a constant pressure chamber. The laminar flame speeds, Markstein lengths and flammability limits were reported for ammonia/methane fuel blends with the equivalence ratios varying from 0.6 to 1.4, at room ...
Tao Shu, Yuan Xue, Zijun Zhou, Zhuyin Ren   +3 more
openaire   +1 more source

The Turbulent Flame Speed of Premixed Spherically Expanding Flames

2017
Premixed syngas/air flames expanding in turbulent flow fields are investigated using large scale direct numerical simulations. A parametric analysis is performed in circular and spherical geometries for the detailed investigation of the interaction between the flame front and the turbulent flow field.
G. K. Giannakopoulos, C. E. Frouzakis, M. Matalon, A. G. Tomboulides   +3 more
openaire   +1 more source

Surface Morphology and Self-Acceleration of Expanding Spherical Flames

47th AIAA Aerospace Sciences Meeting including The New Horizons Forum and Aerospace Exposition, 2009
This paper reports results on the cellular and pulsating instabilities developed over the surface of expanding spherical premixed flames. Regarding the cellular instabilities, experimental data from time-resolved images of hydrogen–air flames exhibiting hydrodynamic and diffusional-thermal cells were used to determine the flame acceleration exponent α,
Grunde Jomaas, C.K. Law
openaire   +1 more source

Modeling of Turbulent Scalar Transport in Expanding Spherical Flames

SAE Technical Paper Series, 2005
<div class="htmlview paragraph">In the first part of the paper, a generalization of the turbulent diffusivity concept is considered and a generalized diffusion coefficient is introduced to account for the development of turbulent diffusivity, pressure-driven countergradient transport, and effects of chemical reactions on turbulent scalar flux ...
Andrei N. Lipatnikov, Jerzy Chomiak
openaire   +1 more source

Nonlinear effects in the extraction of laminar flame speeds from expanding spherical flames

Combustion and Flame, 2009
Abstract Various factors affecting the determination of laminar flames speeds from outwardly propagating spherical flames in a constant-pressure combustion chamber were considered, with emphasis on the nonlinear variation of the stretched flame speed to the flame stretch rate, and the associated need to nonlinearly extrapolate the stretched flame ...
A.P. Kelley, C.K. Law
openaire   +1 more source

Investigations on the cellular instabilities of expanding hydrogen/methanol spherical flame

International Journal of Hydrogen Energy, 2021
Abstract A comprehensive measurement and investigation of the cellularization of methanol/hydrogen flame is important for the thorough understanding of the transition of turbulent flame. In this work, a constant volume combustion bomb with schlieren photography technology is used to study the flame evolution of methanol/hydrogen fuel.
Han Wu, JingXie Zheng, Xu Dong, Saifei Zhang, Yi Ding   +4 more
openaire   +1 more source

End-gas autoignition investigations using confined spherically expanding flames

2021
Propagation of a confined spherically expanding flame induces isentropic compression that can culminate in autoignition and/or detonation under conducive thermodynamic conditions. This relatively simple technique measures a distinct ?characteristic ignition delay time?
openaire   +1 more source

Schlieren and Shadowgraph Images of Transient Expanding Spherical Thin Flames

Energy Conversion, 2002
Experimental facilities have been built to visualize transient expanding spherical flames. Facilities include a cylindrical chamber with two end glasses for optical observation. Shadowgraph and Schlieren pictures of flame propagation have been taken using a high speed Charged Coupled Device (CCD) camera.
Matyas Matlo, Farzan Parsinejad, Hameed Metghalchi   +2 more
openaire   +1 more source