Simulation of Combustion Flow of Methane Gas in a Premixed Low-Swirl Burner using a Partially Premixed Combustion Model

Because the rotational current stabilizes the flame by creating a recirculation zone, it may increase the risk of reversal. For this reason, low-spin combustion is used to stabilize the flame while preventing flashbacks. Therefore, in this study, the combustion flow of methane gas in a low-swirl burner is simulated using a partially premixed combustion model. Furthermore, the fuel flow rate is considered constant. The research parameters include swirl angle(θ=35°–47°), equivalence ratio(φ=0.6–0.9) and inlet axial flow radius(R=0.6–0.7) and effect of these parameters on temperature distribution, flame length, flame rise length, velocity field, and streamlines of the number of pollutant species are investigated. The contours of streamline, temperature distribution, and velocity distribution are also presented for analysis of flow physics. The results show that with increasing the fuel-air ratio, the strength of the axial flow decreases, and the position of the maximum flame temperature shifts toward the inlet of the reactants. The results also reveal that by increasing the swirl angle of the flow, the position of the minimum velocity value(opposite to the direction of the axis) tends towards the outlet. The results also indicate that the maximum temperature of the combustion chamber increases with increasing the swirl angle, and in θ=35°, the maximum temperature is 1711°C and in θ=41°, this value is 1812°C. Finally, by increasing the swirl angle to θ=47°, the maximum flame temperature position is found at a considerable distance from the inlet and is 1842°C.