Spectral Radiation Properties of Super Fuel-Rich Premixed Flame.

Modeling of soot particles growth in fuel-rich premixed flame

“…(24) was estimated from both the mesh number and the calculation region, i.e., the maximum radius of the soot particles. The soot particle coalescence region (radius l) was determined by fitting the absorption coefficient, j soot ðxÞ, and soot particle volume fraction, f v;s ðxÞ, to the corresponding measured values [7].…”

“…Therefore, the soot particle diameter is considered to reach approximately 100 nm in the downstream side. The order of these values corresponds to those for the CH 4 -O 2 flame [19], i.e., mean soot particle radius of 5-80 nm, total soot volume fraction of 10 À8 -10 À5 , and those to spectroscopical measurement [7], i.e., mean soot particle radius of 70 nm, total soot volume fraction of 10 À7 , and the absorption coefficient for luminous flame of 2 m À1 . Fig.…”

“…In recent experiments relating to carbon solidification combustion [1,7,8] a luminous flame was successfully formed at the downNomenclature a frequency factor for soot formation (s À1 ) A frequency factor for exothermic reaction (s À1 ) or endothermic reaction (1/kg/s) A c frequency factor for radical oxidation (m 3 / kg/s) A p surface area of an equivalent particle of porous medium (m 2 ) b frequency factor for radical destruction (m 3 / s) C specific heat of porous medium (J/kg/K) C 0 frequency factor for collision between soot particles and radicals (m 3 /s) C 2 the second Planck's constant (1.4388 · 10 À2 mK) C r dimensionless coefficient, Eq. (24) c p specific heat of gas phase at constant pressure (J/kg/K) D diffusion coefficient (m 2 /s) d p mean diameter of a soot particle (m) E activation energy (J/mol) E n exponential integral function of the nth order, Eq.…”

Experimental study on a compact methanol-fueled reformer with heat regeneration using ceramic honeycomb (third report: observation of reaction structure and its effect on reforming characteristics)

“…Echigo [6] proposed the concept of the radiation converter wherein the enthalpy of the working gas is efficiently converted into radiation emission through highly convective heat transfer between the gas and the solid surface. Okuyama et al [7] also reported that by adding a porous material, which works as a radiation converter and regenerates the energy from the exhaust gas to the unburned mixture, it was possible to stabilize a super-rich flame beyond the flammability limit. This concept of porous radiation converter has been applied to the present reformer to enhance the reforming reaction.…”