超宽狭缝式喷嘴流场数值模拟和射流速度凸度控制

Flow Numerical Simulation and Crown Control of Wide Slot Nozzle

为了开发具有高强度冷却能力且冷却介质流量分布合理的淬火系统超宽狭缝式喷嘴结构,采用有限元法对狭缝式喷嘴射流速度分布进行了数值模拟。结果表明,喷嘴进水方式对出口射流速度分布规律影响较大,通过比较端部进水方式及不同进水口数量的中部进水方式,得出中部进水方式且进水口数量大于4个时,射流速度均匀性最好。保证喷嘴其他结构参数及工艺参数不变,通过改变沿喷嘴长度方向阻尼装置均流孔直径的递减比例系数,来实现出口射流速度的凸度控制,效果明显。随着直径比例系数增大,比例凸度值成线性递增变化。射流速度比例凸度模型可以实现水量的精确凸度控制,为优化设计基于淬火工艺需求的流量分布合理的超宽狭缝喷嘴结构提供指导。

In order to develop quenching slot nozzle structure with high-intensity cooling capacity and reasona- ble distribution of jet velocity, the finite element method was used to simulate the jet velocity distribution along the direction of the slot nozzle. The results showed that water inlet types had a great impact on distribution of jet velocity. Compared with inlet types of nozzle ends, the middle inlet type with more than 4 water inlets had the most uniform outlet jet velocity distribution. Keeping device parameters and process parameters constant, the diameter of uniform orifice was changed to adjust the proportional crown of jet velocity. The diameter was proportional decreased from the middle to two ends along the length direction of the slot nozzle. With the increasing of proportional coefficient of uniform flow orifice diameter,proportional crown of jet velocity increased linearly. The calculation convexity model provided a theoretical guidance for reasonable distribution of jet velocity.