Effect of swirl cup's primary swirl number on ignition performance

All swirl cups have the same primary inclined multi hole and secondary radial straight blade and a simplex pressure atomizer. The effects of primary swirl number of airblast atomizer on small combustion ignition performance were examined. The ignition experiments for swirl cups with three different primary swirl numbers were conducted under atmospheric pressure and temperature in a rectangular reflux combustion chamber, and the pressure drop across the flame tube was between 0.5% and 5% of inlet total pressure. The experimental results show that the primary swirl number significantly influence the ignition performance. Under the same pressure drop, within a certain range, the increase of primary swirl number affects the downstream flow field distribution, which is beneficial for fire nuclear spreading along the upstream of recirculation region and forming a steady flame in the swirl cup exit. So the swirl cup with strong primary vortex has better ignition performance.