Turbulence-Radiation Interaction Effects on Liquid Fuel Droplet Evaporation in Spraying Combustion Flow Using Large Eddy Simulation

Abstract

The objective of the present article is to address the influence of turbulence-radiation interactions (TRI) on parameters associated with the evaporation rate of fuel droplets in the spray combustion of a fuel mixture containing \({\text{C}}_{10}{\text{H}}_{22}\) within a model combustor. Variables such as turbulence kinetic energy, TRI factors, and temperature distributions, particularly at the sub-grid scale, are investigated utilizing the large eddy simulation approach. Also, parameters including the pattern factor and \(\text{NO}\) concentration at the combustor outlet are assessed. The Eulerian approach to simulate the gaseous phase and the Lagrangian approach to model the liquid phase are employed. A two-way is used to couple their interactions, excluding the secondary breakup due to the Weber number being less than unity. The wall-adapting local eddy-viscosity model is adopted to simulate the eddy viscosity. The discrete ordinates method with the weighted-sum-of-gray-gases model is applied for thermal radiation calculating absorptivity and emissivity. The probability density function is utilized for modeling combustion. Results indicate that considering TRI facilitates the vaporization of fuel droplets due to accelerating the breakup process of the largest droplets by 3.36%, increasing their volumetric heat capacity by 4.50%, and reducing the penetration length by 10 mm. Furthermore, the maximum \(\text{NO}\) pollutant concentration at the combustor outlet decreases from 11.64 to 9.84 ppm, and PF reduces from 0.034 to 0.011 in the presence of both resolved and sub-grid scale TRI.