金属熔滴碰撞、铺张数值分析

A numerical analysis on the metal droplets impacting and spreading out on the substrate

摘要:

基于金属熔滴沉积成形的3D打印技术,其成形质量与金属熔滴及基板参数有很大关系。本文对金属铝熔滴在不同参数下,比如：熔滴直径、滴落速度、比热、导热系数、潜热以及基板温度等,其凝固过程中的最大铺展因子关系进行了研究。采用VOF对自由表面进行追踪的方法,建立包括对流和相变的计算方程和能量方程的仿真模型,耦合水平集函数,跟踪熔融粒子与周围空气之间的接口,获得的最大传播因子之间的关系,与在文献中出现的实验数据吻合。

Abstract:

The quality of 3D printing parts obtained by means of droplets deposition depends strongly on the mechanism of the interaction between the molten metal droplets and the substrate to be covered. The effects of various parameters such as impact velocity, substrate temperature, droplet diameters, specific heat, thermal conductivity, latent heat on the maximum spread factor during impacting and spreading with solidification of a molten droplet onto an aluminum surface under different parameters was studied. The free surface of the droplet was tracked by the volume-of-fluid (VOF) method. The simulation model was based on the N-S equations and the energy equations which include convection and phase change. These equations were coupled with the Level Set function to track the interface between molten particles and surrounding air. The maximum spread factors were obtained and were in agreement with the experimental data available in the literature.