| Abstract:The swirling direction of a swirl cup airblast atomizer and its downstream confined space will affect the shape, size, and
position of large-scale vortices downstream of the nozzle, thus affecting the distribution of fuel droplets in space. Aiming at the problem of
uneven droplet distribution downstream of the airblast atomizer, the influence of the combinations of the downstream confined space of the
airblast atomizer and the swirling direction of the swirler on the particle size of the fuel droplet was studied by a combination of experiment
and numerical simulation. The results show that the large-scale backflow paired-vortices generated by the airblast atomizer with a two-
stage counter-swirl scheme in the downstream confined space has stronger entraining and converging ability to the droplets, and the
measured droplet Sauter Mean Diameter (SMD) is larger than that of the two-stage co-swirl scheme, with a maximum value of 26 μm.
When the radial diameter of the downstream confined space of the airblast atomizer increases from 133 mm to 173 mm, the backflow
paired-vortices increase from one pair to two pairs, the degree of fuel droplets converging upstream along the axial direction increases, and
the droplet SMD measured in the confined space with a diameter of 173 mm increases by 3-5 μm with different fuel supply pressures
compared to the droplet SMD in the space with a diameter of 133 mm. The closer the distance between the measurement position and the
large-scale vortex structure, the stronger the entraining and converging effect of the large-scale vortex on the surrounding droplets, and the
larger the SMD of the droplets at the measurement position. |
