Atomization of misaligned impinging liquid jets

This study numerically investigated the atomization characteristics of misaligned impinging jets, with the misalignment ratio ê ranging between 0 and 0.2, by employing the volume of fluid method with an adaptive mesh refinement algorithm. The results show that the droplet Sauter mean diameter varies non-monotonically with ê and reaches the minimum value, which implies the best atomization performance, at ê=0.1 under operating conditions concerned in the present work. Meanwhile, the moderately misaligned impingement also leads to a more uniform spatial dispersion of the atomized fragments and droplets. These unique spray behaviors can be attributed to the instability and disintegration of the liquid sheet formed upon jet impingement, as evident from the non-monotonic dependence of the breakup length of the liquid sheet on the misalignment ratio ê. Analyses on the velocity fluctuation and vorticity distribution further suggest that the misalignment alters the intrinsic instability mode of the liquid sheet by introducing a lateral stretch effect, which diverts the peak streamwise momentum away from the centerline. The current finding indicates that misalignment tuning could be a promising optimization and control technique in propellant mixing and atomization.