To study the atomization characteristics of pintle injectors

the influences of structural parameters of pintle injectors on Sauter mean diameter (SMD)

drop distribution homogeneity factors and atomization cone angles were obtained by using high-speed photography and Marvin measuring instrument. The results indicated that SMD kept constant along the injection axis direction

and increased along the radical direction. In addition

with the increase of gas-liquid mass flow ratio SMD decreased

but the drop distribution homogeneity factors reduced firstly and then increased. The product of drop distribution homogeneity factors and slit width kept constant

which was 0.35. When the gas-liquid mass flow ratio was larger than 0.206

with the effects of aerodynamic force

the atomization boundary could be divided into two zones

the upper zone as the contraction stage

and the lower zone as the equal-diameter stage. Moreover

when designing pintle injectors

the slit width should be chosen as small as possible

while the half cone angle of liquid film should be selected according to SMD and atomization cone angles.