A challenge to vapor distribution measurement of multi-component evaporating fuel spray via laser absorption-scattering (LAS) technique

In the present study, a challenge has been made to quantitatively determine the vapor phase concentration distributions in an evaporating multicomponent fuel spray using the LAS imaging technique. The theoretical considerations were particularly given when applying the LAS imaging technique to the multicomponent fuel spray and reconstructing the vapor concentration distributions from the spray images. In practice, measurements of the vapor concentration distributions of the lower (n-tridencane) and higher (n-octane) volatility components in the binary component fuel sprays have been carried out at ambient temperatures of 473K and 573K, by substituting p-xylene for n-octane or α-methylnaphthalene for n-tridecane. p-Xylene and α-methylnaphthalene were selected as the substitutes is because they have strong absorption band near 266nm (the fourth harmonic of an Nd:YAG laser) and transparent near 532nm (the second harmonic of an Nd:YAG laser) and, their thermo-physical properties are similar to those of the original component. As a demonstration experiment, vaporization characteristics of the lower boiling point (LBP) and higher boiling point (HBP) components in the binary component fuel spray have been obtained. The vapor measurement error for the binary component fuel spray has been estimated up to maximum 38% for p_xylene in “p-xylene_tridecane” fuel spray and 27% for α-methylnaphthalene in “α-methylnaphthalene_n-octane” fuel spray.