In order to investigate the effect of dual axial swirler Venturi length on flow field and spray characteristics

the flow field downstream the dual axial swirler outlet for four different Venturi length dual axial swirlers was simulated and matched with fuel nozzle to test the spray characterization. The results showed that the 2ed swirler’s discharge coefficient was 0.75 constantly

while the 1st swirler’s discharge coefficient decreased from 0.98 to 0.7

the swirler outlet swirl number increased from 0.08 to 0.48

and the downstream flow field from inside-out recirculation zone turned into conventional recirculation zone as the dimensionless length of Venturi increased from 0.23 to 0.49. Spray cone angle and Sauter mean diameter (SMD) of shortness Venturi length case were less affected by air pressure drop across from swirler

however

the other cases’ spray cone angle and SMD were strongly affected by air pressure drop across from swirler

and SMD and spray cone angle increased as Venturi length increased under the same fuel mass flow rate and air pressure drop.