造雪機用旋流噴嘴霧化特性的模擬研究
Numerical study on atomization characteristics of swirl nozzle for artificial snowmakers
摘要：
旋流噴嘴作為造雪機關鍵部件，其霧化效果直接影響成雪效果。為進一步探索旋流噴嘴霧化特性，基于VOF to DPM模型，建立旋流噴嘴霧化的數值模型，對旋流噴嘴進行三維數值模擬。研究不同入口壓力對液滴粒徑、液滴速度等霧化特性的影響，并通過實驗驗證了模型的準確性。結果表明，噴霧充分發展后，索特平均粒徑隨入口壓力的增大而減小，入口壓力增大，增強了液體和空氣之間的氣動不穩定性，促進了液體的破碎分解，縮短了液體所需破碎時間；液膜和液滴速度都隨著入口壓力的增大而增大，當入口壓力由0.6 MPa增大到1.4 MPa時，出口液膜和液滴速度分別增加58.8%和52.2%；在破碎過程中，動能轉化為表面能，會使液體速度發生削減。
Abstract：
Swirl nozzle is regarded as the key component of on artificial snowmaker, its atomization effect directly affects the snow quality. A three-dimensional numerical model of swirl nozzle atomization is established based on VOF to DPM model, in order to further explore the atomization characteristics of swirl nozzle. The effects of inlet pressure on the atomization characteristics such as droplet size and velocity are studied, and the accuracy of the model is verified by experiments. The results show that after full development of spray, the Sauter mean diameter decreases with the increase of inlet pressure. The rising pressure enhances the aerodynamic instability between liquid and air, promotes the liquid breakup, and shortens the breakup time of liquid. The velocity of liquid film and droplet both increase with the rising inlet pressure. With the inlet pressure increasing from 0.6 MPa to 1.4 MPa, the velocity of liquid film and droplets can increase by 58.8% and 52.2%. Moreover, during the breakup process, the conversion of kinetic energy into surface energy reduces the liquid velocity.
Keywords:swirlnozzle;artificialsnowmaker;atomizationcharacteristic;snowmakingtime;numericalsimulation