燃油喷嘴雾化空化特性数值模拟分析

Numerical Simulation Analysis of Atomization Cavitation Characteristic of Fuel Nozzle

燃油喷嘴雾化质量对保障车辆尾气排放质量具有重要意义。利用气液多相流模型,研究燃油喷嘴雾化空化特性。通过数值模拟分析燃油喷嘴入口压力对气相体积分数、燃油流动速度、空化因数的影响。在相同燃油喷嘴入口压力下,随着入孔角因数的增大,燃油空化现象明显减弱。空化因数随燃油喷嘴入口压力的增大而增大,并且增大速率较快。增大燃油喷嘴入口压力能够起到较好的雾化效果,但是会带来空化因数的增大。选取合理的燃油喷嘴入口压力,是保证雾化质量的关键。

The atomization quality of fuel nozzle is of great significance to ensure the quality of vehicle exhaust emission.The gas-liquid multiphase flow model was used to study the atomization cavitation characteristic of fuel nozzle.The effects of the inlet pressure of fuel nozzle on gas phase volume fraction,fuel flow velocity and cavitation factor were analyzed by numerical simulation.Under the same inlet pressure of the fuel nozzle,the fuel cavitation phenomenon is significantly weakened with the increase of the hole inlet factor.The cavitation factor increases with the increase of the inlet pressure of fuel nozzle,and the increase rate is faster.Increasing the inlet pressure of fuel nozzle can have a better atomization effect,but it will increase the cavitation factor.Choosing a reasonable inlet pressure of fuel nozzle is the key to ensuring the atomization quality.