Droplet Number Spectra in the Jet Atomization Regime

A previous model [1] to determine the number spectra of droplets generated by the injection of a fluid into another fluid is extended to cases of instantaneous disruption (near-zero jet breakup time). Under this scenario, droplets immediately form at the injection nozzle from unstable antisymmetric jet-surface waves. Resulting droplet characteristics only depend on the initial jet-surface disturbance. Full atomization is attained as the jet fluid is consumed by a series of successive droplet formation events that peel away the jet surface. The model is applied when the initial jet-surface disturbance is represented as broad-band white noise: each peel is characterized by a selected wave amplitude and high-cutoff wavenumber. Very good agreement was observed between model results and experimental droplet number spectra [2] obtained in the atomization regime.