增强反应注射成型机混合头内流体高压高速对撞过程模拟与分析

Simulation and analysis of fluid high-pressure and high-speed collision in mixing head cavity of enhanced reaction injection molding machine

以型号为MK-8/12UL-2K的L形混合头为模型,运用了CFD数值模拟软件对混合头腔内两相物料流体的高压高速对撞进行了模拟分析。通过控制变量法分别探究了流量和黏度对混合结果的影响,同时为了更好地表征玻璃微珠在混合过程中的运动情况,还对整个流场进行了粒子示踪分析。结果表明,增加质量流量会导致混合腔内速度压力的提升,也就是对撞程度变高,对撞的位置会更加偏向于黏度高的物料出口侧;增加黏度会导致混合腔内物料的压力提升速度降低,同时对撞的位置会明显更加偏向于黏度高的物料出口侧,且摩擦力显著增加;粒子停留时间则随质量流量的提高而减短,随物料黏度的提高而增加;通过模拟获得的这些结果为混合头设计及工艺优化工作提供了一定的参考价值。

An L-shaped mixing head model with a version number of MK-8/12UL-2K was used to simulate and analyze the high-pressure and high-speed collision of two-phase material fluid in the mixing head cavity using a CFD numerical simulation software. The effects of flow rate and viscosity on the mixing effectiveness were investigated using a controllable variable method. To better characterize the motion of glass beads in the mixing process,particle tracer analysis was carried out on the whole flow field. By comparing the pressure and velocity cloud diagram,it is concluded that the increase of mass flow leads to an increase in velocity pressure in the mixing chamber. This means that the collision degree becomes higher and the collision location becomes more inclined to the outlet side of the material with a high viscosity.The increase of viscosity resulted in a decrease in the pressure lifting speed of the material in the mixing chamber. The collision position was more inclined to the outlet side of the material at a high viscosity,resulting in a significant increase in friction force. The particle residence time decreased with an increase in mass flow rate but increased with an increase in viscosity. The simulation results provide a certain reference value for the design and processing optimization of mixing heads.