Effect of Acoustic Perturbations on Liquid Jet Atomization

The effect of unsteady chamber characteristics on the atomization process is investigated using nonlinear free-surface models based on boundary element methods. Two separate scenarios are considered. In the e rst case, a liquid column is subjected to transverse oscillations from the gas phase. The second calculation addresses dynamic orie ce mass e ow caused by the presence of longitudinal acoustic perturbations. Results indicate that the atomization process can be strongly affected by these perturbations. As expected, the most prominent coupling occurs at driving frequencies that are at (or near) the natural frequency of oscillation of the liquid. Nomenclature a = orie ce radius Im = modie ed Bessel function of the e rst kind, order m Km = modie ed Bessel function of the second kind, order m k = wave number n = mode number for column excitation, Eq. (5) P = pressure q = velocity normal to local surface r = radial coordinate t = time U = velocity We = Weber number, rgU 2 a/s = rU 2 a/s in Figs. 8 ‐ 12 x = horizontal coordinate y = vertical coordinate z = axial coordinate « = density ratio, rg/r k = surface curvature r = density s = surface tension f = velocity potential v = oscillation frequency Subscript g = gas phase Superscript ˆ = perturbation quantity