NUMERICAL INVESTIGATION INTO THE EFFECT OF AIR SWIRL ON NON-PREMIXED COMBUSTION

Endeavour is made to investigate the effect of swirled air on methane-air combustion in a Harwell combustor geometry. The inlet air swirl intensity on combustion characteristics such as temperature, pollutant formation, and flow dynamics is studied. The modeling of turbulent characteristics is performed with the standard K-epsilon model using ANSYS Fluent. Eddy dissipation model with one step reaction is used for modeling chemical reaction and P-I radiation model for radiation heat transfer. The swirl number is achieved in the range of 0.0 to 0.6, by varying the tangential velocity to the air inlet. With the increase in swirl intensity, the maximum flame temperature drops, and most of the flame formation shifts towards the inlet of the furnace. The change in the flow field is aided by the formation of recirculating bubbles. The swirl causes the flame to spread radially away from the axis, thereby increasing the heat transfer flux to the furnace wall. As a result, a significant reduction in the formation of NO pollutants is observed.