Numerical analysis of the nonlinear instability of monolayer and compound liquid capillary jets
by
M.S. Kaschiev
Institute of Mathematics and Informatics, BAS
Coauthors: M. Koleva (Institute of Mathematics and Informatics - BAS), F. Onofri, L. Tadrist (Institute Universitaire des Systemes Thermique Industriels, Universite de Provence, Technopole de Provence, Marseille), St. Radev (Institute of Mechanics - BAS)

The nonlinear instability of two different axisymmetrical configurations of liquid capillary jets is studied on the basis of the nonsteady one-dimensional approximation of the equations of motion. Neglecting the gravity both the undisturbed radius and axial velocity of the jet are assumed constant along its axis.

The perturbed flow is considered spatially periodical of a given wave length. At the initial time the jet is excited by a disturbance, assigned in the form of a series of one fundamental and several higher harmonics of prescribed amplitudes and different phases corresponding to the linearized jet instability problem. A numerical solution is proposed for following the evolution of the imposed disturbance in time close to the jet break-up. It is shown that the form of the jet disintegration concerning the forward and backward merging of the resuling satellites could be controlled by the number and amplitudes of the initial harmonics as well as by their phase shifts.

Date received: January 31, 2000