基于Fluent的3D打印机成型腔内气固两相流动特性

Gas-solid two-phase flow characteristics inmolding cavity of 3D printer based on Fluent

基于计算流体力学(computational fluid dynamics,CFD)方法对3D打印设备成型腔内流道气固两相流流动特性进行数值模拟,结合一种小型3D打印机建立物理模型,应用固体颗粒轨迹追踪的方法分析该3D打印设备成型腔内部产生大量烟雾的原因,对目前实际生产过程中产生问题进行解释;通过改变吸气孔高度、吹吸气孔距加工平台高度,定性分析其对腔体内产生烟雾量的影响。结果表明:实际加工过程中腔体内部产生大量烟雾的原因是层流气体发散严重,使箱体内部产生涡流现象,增加固体小颗粒在成型腔内部滞留时间;通过吹吸罩除尘理论对该型3D打印设备吸气孔高度进行理论计算,当吸气孔高度为32 mm,吹吸气孔距加工上表面高度为32~37 mm时烟雾量可以达到最小。

The flow characteristics in molding cavity of 3D printer equipment were numerically simulated based on computational fluid dynamics(CFD).Physical model was built with a small 3D printer.The reason for the large amount of smoke in the forming chamber of the 3D printing equipment was analyzed using the method of solid particle track tracing,and the problems were explained in actual production process.Regularities were qualitatively analyzed which impacted by changing the height of the blow hole and the distance between the blowing and suction holes in the chamber.The results show that the serious laminar gas diffusing is the reason for the large amount of smoke in the cavity.Eddy current phenomenon is produced inside and the retention time of small solid particles in the cavity is increased.The amounts of smoke in the chamber can be minimized when the height of the blow hole is 22 mm and the distance is 32〜37 mm between the blow hole and the upper surface.