A new multicomponent formulation, appropriate for use with the finite-volume method, has been developed to describe mass diffusion velocities accurately. The new formulation is applied in a quasi-steady numerical model for n-heptane fuel droplet combustion in a forced-convection environment. Results obtained using the complete formulation are compared to the results obtained under various assumptions. Using a single binary diffusion coefficient produces results for extinction velocity, maximum temperature, flame dimensions, evaporation constant, and drag coefficient that are significantly different from the results obtained using the complete formulation. Neglecting thermal diffusion (Soret effect) causes only minor changes (less than 2%).
Acknowledgments
This research was partially funded by NASA EPSCoR under Grant NCC5-401 and ARO EPSCoR under Grant DAAD19-99-1-0116. Computational resources were provided by the Thermal/Fluids Computational Facility at the University of Nebraska–Lincoln.