Effect of morphological oscillation and internal flow on droplet impact, spreading, and solidification on a solid surface

摘要

The effect of internal flow and morphology at impact on the spreading behavior of a droplet impinging on a solid surface is investigateed. The approache chosen in the present study is numerical simulation. The free surface flow resulting from the droplet impact on a solid surface is modeled using two-dimensional ax-isymmetric Navier-Stokes equations combined with a volume of fluid fraction transport equation. When solidification is considered, the solidification process is described using a locally 1D, ulti-directional algorithm. Morphological deformations of practical interest such as spheroids and superposed semispheroids are considered. Internal flow is simulated by specifying the initial velocity field. For instance, the velocity field caused by a Hill's vorext is used to simulate shear-induced internal circulation. Finally, the effect of these phenomena on the droplet solidification behavior is studied. The results show that while the effect of internal circulation is essentially negligible, droplet deformation should be included in the simulation of droplet spreading and solidification.