Nonlinear capillary waves on swirling, axisymmetric free liquid films

The nonlinear distortion and breakup of a swirling axisymmetric thin invisc id liquid sheet in a void and at zero gravity is analyzed by means of a red uced dimension approach. Nonlinear steady-state solutions are presented for various boundary conditions imposed at the nozzle exit. Unsteady solutions describing the nonlinear breakup of the radially expanding film due to dil ational or sinuous modulations at the nozzle exit are presented. Fluid ring s with thin connecting shells are formed due to nonlinear effects and sheet thinning caused by sheet divergence is found to increase nonlinear breakup lengths and times for both sinuous and dilational modes. For the case of a swirling annular liquid sheet, comparisons are made with an annular sheet which is stabilized by a constant gas-core pressure. Here, swirl causes a r eduction in breakup lengths and times. (C) 2001 Elsevier Science Ltd. All r ights reserved.