Statistical relationship between soot volume fraction, temperature, primary particle diameter and OH radicals along transects normal to the local reaction zone in a turbulent flame

2020 ◽  
Author(s):  
Zhiwei Sun ◽  
Bassam Dally ◽  
Zeyad Alwahabi ◽  
Graham Nathan
Keyword(s):  
Reaction Zone ◽  
Primary Particle ◽  
Volume Fraction ◽  
Local Reaction ◽  
Turbulent Flame ◽  
Particle Diameter ◽  
Soot Volume Fraction ◽  
Oh Radicals ◽  
Statistical Relationship ◽  
Primary Particle Diameter

A Numerical and Experimental Study of Soot Precursor and Primary Particle Size of N-Butylbenzene in Laminar Flame

2021 ◽  
Author(s):  
Mingshan Sun ◽  
Zhiwen Gan
Keyword(s):  
Soot Particle ◽  
Primary Particle ◽  
Volume Fraction ◽  
Soot Formation ◽  
Laminar Flame ◽  
Particle Diameter ◽  
Soot Volume Fraction ◽  
The Core ◽  
Soot Precursor ◽  
Combined Mechanism

Abstract The current study analyzed the soot precursor of the n-butylbenzene found in diesel and kerosene in laminar flame, and integrated the corresponding poly-aromatic hydrocarbon (PAH) growth mechanism with the popular n-butylbenzene oxidation mechanisms to improve the soot formation prediction of n-butylbenzene. The size of soot precursor was determined by the fringe length in the core of soot particle since the nanostructure of the core of soot particle is similar with that of nascent soot particle formed by soot precursor nucleation. The geometric mean fringe length in core of soot particles was measured to be 0.67 nm approximating to the size of five-ringed PAH (A5). An A5 growth mechanism was added on a popular n-butylbenzene mechanism, and the combined mechanism was further reduced. After validation by the ignition delay time in literature, the combined mechanism was then validated by the primary particle diameter in laboratory and soot volume fraction of n-propylbenzene in literature. The calculated soot precursor concentration and PAH condensation rate of the combined mechanism are smaller than that of the base mechanism. The simulated primary soot particle diameter of proposed combined mechanism agrees well with the measure primary soot particle diameter. Comparing to the simulated soot volume fraction of base n-butylbenzene mechanism, the simulated soot volume fraction of proposed combined n-butylbenzene-A5 mechanism agrees well with the measure soot volume fraction of n-propylbenzene in literature. This study provides certain support for further investigation of soot formation of n-butylbenzene and its relative fuel like diesel and kerosene.

scholarly journals Acceleration and heating of metal particles in condensed matter detonation

2012 ◽  
Vol 468 (2142) ◽  
pp. 1564-1590 ◽  
Author(s):  
Robert C. Ripley ◽  
Fan Zhang ◽  
Fue-Sang Lien
Keyword(s):  
Reaction Zone ◽  
Volume Fraction ◽  
Density Ratio ◽  
Particle Diameter ◽  
Solid Particles ◽  
Metal Particles ◽  
Solid Loading ◽  
Shock Propagation ◽  
Zone Length ◽  
Detonation Shock

For condensed explosives, containing metal particle additives, interaction of the detonation shock and reaction zone with solid inclusions leads to high rates of momentum and heat transfer that consequently introduce non-ideal detonation phenomena. During the time scale of the leading detonation shock crossing a particle, the acceleration and heating of metal particles are shown to depend on the volume fraction of particles, dense packing configuration, material density ratio of explosive to solid particles and ratio of particle diameter to detonation reaction-zone length. Dimensional analysis and physical parameter evaluation are used to formalize the factors affecting particle acceleration and heating. Three-dimensional mesoscale calculations are conducted for matrices of spherical metal particles immersed in a liquid explosive for various particle diameter and solid loading conditions, to determine the velocity and temperature transmission factors resulting from shock compression. Results are incorporated as interphase exchange source terms for macroscopic continuum models that can be applied to practical detonation problems involving multi-phase explosives or shock propagation in dense particle-fluid systems.

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