(368d) Multicomponent Fuel Spray Evaporation in High Pressure Hot Gas Flows

In this study, we investigate multicomponent fuel droplet dispersion and evaporation in a hot gas flow with elevated pressure environment. A new modeling methodology to simultaneously account for finite thermal conductivity, finite mass diffusivity and turbulence effects within atomizing multicomponent liquid fuel sprays has been developed. This new model incorporated the liquid turbulence effect in modeling the boundary layer heat and mass resistance during multi-component droplet evaporation. The atomization/spray model used is the T-blob/T-TAB model developed by the authors. This model supplies relevant turbulence characteristics within the atomizing droplets from the injector. The finite conductivity and mass diffusivity models are based on two-layer film theory, where the turbulence characteristics of the droplet are used to estimate the effective thermal conductivity and mass transfer diffusivities. Real fuels such as gasoline, diesel and bio-derived fuels are replaced by surrogate fuels based on a newly developed methodology using the inversed batch distillation concept. In the droplet model four regions are considered: the interior region of the droplet, droplet-side interface, gas-side interface, and the surrounding gas phase. Approximate solutions to the quasi-steady energy and mass transfer equation were used to derive an explicit expression for the heat and mass flux from the surrounding gas to the droplet–gas interface, and within the multi-component droplet. At the droplet/gas interface, extension of the phase equilibrium model to high pressures using the Peng-Robinson equation of state and activity coefficient is also considered. So far, the model has been validated with one-way coupled numerical calculations. The purpose of this study is to incorporate the KIVA-3V computational fluid dynamics (CFD) code utilizing hybrid Large Eddy Simulation for two-way coupled droplet-fluids interactions. Validations against available experimental data will be performed and discussed.