NOx formation of spray combustion at different OH models under equilibrium oxygen conditions

Abstract

This work employs partial and non-OH models to mimic 2D steady-state spray combustion. The study examines the status of the partial OH model following the NOx forecast, comparing it to the non-model. It assumes that the O model is in equilibrium with the predicted NOx. The study assesses the numerical models by using data from Mao et al. (35). This study used n-pentane as the fuel and ambient air as the oxidant in a turbulent flame characterized by non-premixed combustion. The mixture fraction-probability density function model is used to solve chemical kinetics. Fluent 15.0 software performs numerical simulation of two-phase flow and combustion modeling for pollutant formation. The k−ε turbulence model was used to solve the conservation equations for mass, momentum, and energy in turbulent flow fields. A simulation was performed using a thermal NOx mechanism to compute NOx formation. This study investigated the velocity components in the gas phase, the mass fraction of NOx, the NOx rate, the turbulence kinetic energy, and the dissipation rate. Due to state stability, the instantaneous and partial OH models were equivalent, whereas the non-OH model was lower than the partial model. The NOx prediction predicted this temperature variation in response to NOx formation. The NOx mass fraction varies by 0.09% between the partial and non-OH models, and the NOx rates exhibit a 0.09% variation between these models. Across all tested domains, the non-OH model effectively decreased all variables, including NOx emissions.