Modeling Fuel Spray Vapor Distribution With Large Eddy Simulation of Multiple Realizations

Abstract

A state-of-the-art spray modeling methodology, recently presented by Senecal et al. [1, 2, 3], is applied to Large Eddy Simulations (LES) of vaporizing sprays. Simulations of non-combusting Spray H (n-heptane fuel) from the Engine Combustion Network are performed. Adaptive Mesh Refinement (AMR) cell sizes of 0.03125 mm to 0.25 mm are utilized to further demonstrate grid convergence of the Dynamic Structure LES model for diesel sprays. Twenty-eight different realizations are simulated by changing the random number seed used in the spray submodels. Multi-realization (ensemble) averaging, which has been shown to be necessary when comparing to local spray measurements, is performed. Global quantities such as liquid and vapor penetration are compared, as well as local mean mixture fraction and mixture fraction standard deviation. The results suggest that the current model does a reasonable job predicting the major features of the n-heptane spray when appropriate grid resolution is utilized.