Nonlinear Oscillations of Viscous Droplets

This paper deals with the problem of non-linear droplet oscillations, whereas eeects of liquid viscosity are of our special interest. In the experimental part nite amplitude, axial-symmetric oscillations of small liquid droplets in a gaseous environment are studied. Experimental results are compared with available theoretical models. It was found that for a wide range of viscous damping the numerical model, based on applying a least squares approximation to the boundary conditions and the vorticity equation 1], provides results which are in a good agreement with the experimental ndings. At low and medium viscosities also a simplèmechanical' model 2] of droplet dynamics offers adequate description of the numerical and experimental data. The linear irrotational model of Lamb 3] suuers serious discrepancies between predicted and observed oscillation patterns.