Numerical study of diesel-biodiesel blends in 1D freely propagating premixed flames.

HERNANDO MALDONADO; DARIO ALVISO; JUAN CARLOS ROLON; NASSER DARABIHA

Rio de Janeiro

Congreso; 23rd ABCM International Congress of Mechanical Engineering - COBEM2015; 2015

ABCM

Diesel is a complex real fuel, which is derived from conventional petroleum sources, and is composed of hundreds of compounds. These characteristics indicate the difficulty of using this fuel for numerical studies. In order to avoid these difficulties, simplified synthetic fuels, called "surrogate fuels" are used. On the other hand, biodiesel is acomplex mixture of methyl esters with different chain lengths and degrees of unsaturation and can be used in pure form or may be blended with diesel without major modifications in diesel engines. However, changing the fuel in diesel engines induces changes in combustion behavior, which can impact pollutants emission. Therefore, a better understanding of diesel-biodiesel blend combustion is needed. This paper presents numerical studies of diesel-biodiesel blends combustion in a 1D freely propagating gaseous premixed flame configuration. We have developed and validated a new chemicalscheme by carefully combining two schemes availble in the literature: one for diesel and one for biodiesel. This guarantees reproducing the principal features of both fuels combustion characteristics. The new combined scheme, consists of 235 species and 1113 elementary reactions. Laminar flame velocities were obtained as a function of equivalence ratio for different diesel-biodiesel blends. And the new combined model was validated comparing flame velocities of pure diesel and pure biodiesel using the combined model and the original models.