Modeling of heating and evaporation of Primary Reference Fuels and Toluene Reference Fuels

Modeling of the heating and evaporation processes of Primary Reference Fuel 'PRF' and Toluene Reference Fuel 'TRF' are reported. Five different fuel mixtures are considered with initial mass fractions of 100% heptane, 100% iso-octane, 100% toluene, 50% iso-octane + 50% heptane, and 50% toluene + 50% heptane. The analysis is based on the Effective Thermal Conductivity, 'ETC', and the Effective Diffusivity, 'ED', models. These two models take into account the effect of finite thermal conductivity and finite liquid diffusivity, respectively. Both models take into account the effect of internal circulation in the moving droplets. It is pointed out that increasing the initial heptane mass fraction in both PRF and TRF mixture droplets decreases the droplet evaporation time and the droplet surface temperature. Two heating up periods are noticed for the case of 50% iso-octane + 50% heptane mixture droplets, but not for droplets of 50% toluene + 50% heptane. It is shown that the droplet surface, average and central temperatures are well separated and also the differences between surface and average mass fractions are significant. These observations highlight the practical importance of the ETC and ED models when studying heating and evaporation of multi-component droplets.