液滴撞击壁面的飞溅运动

Splashing After Droplets Impinging on a Dry Wall

飞溅运动是液滴撞击壁面运动的一种重要形态,对液滴碰壁的后续运动具有重要的影响.采用气液两相流动相界面追踪的复合Level Set-VOF方法和壁面润湿模型,进行了液滴撞击壁面飞溅运动的数值求解.根据液滴撞击壁面时的能量守恒关系,建立了液滴撞击壁面飞溅运动临界条件的理论模型,并给出了液滴撞击壁面后是否发生飞溅的判据.采用数值方法对液滴撞击壁面发生飞溅运动的机制进行了研究,结果表明,液滴撞击壁面后产生倾斜向上且脱离壁面的射流以及射流液体局部毛细波波长大于毛细破碎临界波长是发生飞溅现象需要满足的两个重要条件.

Splashing is an important movement form when droplets impinged on a dry wall and has an important effect on the characteristics of the impinged wall movement of the droplet. Based on the com- bined Level Set-VOF method for gas-liquid interface tracking and the wall wetting model, the numerical solution of the splashing movement of the droplet impinging on a dry wall was carried out. The theoretical model of the splashing critical condition was established according to the energy conservation, and the splashing criterion for the droplet impinging on a dry wall was put forward based on the theoretical model. The movement of splashing after a droplet impinging on a dry wall was studied. It was found that the in- clined upward jet away from the wall and the local capillary wavelength of the jet which is larger than the critical wavelength are the two essential conditions for the generation of splashing.