旋流喷嘴结构的模拟优化

Simulation and Optimization of Swirl Nozzle Structure

采用CFD软件对旋流喷嘴内流场进行了模拟研究。首先分析了喷嘴入口截面形状分别为圆形、矩形时流体的速度分布、气液接触情况以及出口雾化效果,确定喷嘴的最佳入口截面形状为圆形,在此基础上进一步进行了喷口结构的优化,研究了无喉颈段喷嘴喷口直径分别为10 mm、7.5mm、5 mm时的流场分布情况,选取最适喷口直径为7.5 mm。模拟结果发现,在圆形截面入口喷嘴的基础上选取合适的喷口直径,可以得到连续性较好的空气芯,可改善气液接触情况,有助于出口液膜的减薄破碎,从而获得比较理想的流场分布情况和出口雾化效果。

The internal flow field of swirl nozzle was simulated by using software CFD. First, with the nozzle inlet cross section shape of circular and rectangular, the velocity distribution, gas-liquid contact condition and atomizing quality at the outlet were analyzed. It was determined that the optimum inlet section shape is circular. Then the nozzle structure optimization was further carried out, the flow field with the nozzle exit diameter of 10, 7.5 and 5 mm was studied respectively. It can be found that the optimum nozzle exit diameter was 7.5 mm. The results showed that continuous air core was formed based on circular entrance section with outlet diameter of 7.5 mm, also the gas-liquid contact condition was improved and the it was helpful in making liquid membrane thinned and broken, so the ideal flow field distribution and atomizing quality were obtained.