Numerical Simulation of NOx Formation in a Premixed Methane–Air Flame near a Cold Wall

This paper presents the results of direct numerical simulations of combustion in a conical methane–air flame impinging on a cold flat wall. Three cases with different distances between the burner nozzle and the wall are considered. The study focuses on nitrogen oxide formation in the near-wall region. It has been established that when the wall is located at a distance of three nozzle diameters from the nozzle exit, a recirculation zone is formed between the conical flame front and the cold wall, where an increased concentration of nitrogen oxides NOₓ is observed. This effect of enhanced NOₓ formation disappears in the near-wall region further downstream.