直射式喷嘴可压缩流动模拟分析

Simulation Analysis of Compressible Flow of Direct-fired Nozzle

喷嘴在众多领域中都有广泛的应用,尤其车辆燃油系统的燃油效率与喷嘴有着密切的关系,分析研究喷嘴内流动特性有利于更好地优化其结构,节省燃油能耗,尽可能降低污染物排放,缓解环境压力。文章将喷嘴结构进行简化,应用Fluent软件对在二维喷嘴内的瞬态流动进行模拟分析,得到内部流场的速度、压力、及马赫数随时间的变化情况。结果表明:在流体刚进入喷嘴内时,流体的速度随时间增大,整个喷嘴内在喉部处流体有最大速度;之后当喉部流速达亚音速后,由于漩涡产生内部发生波动,流速呈降低趋势,波动消失后流速缓慢回升,最后流场达稳定状态。

Nozzles are widely used in many fields.In particular,the fuel efficiency of vehicle fuel systems is closely related to nozzles.Analyzing and studying the flow characteristics of nozzles is beneficial to better optimize its structure,save fuel energy consumption,and reduce pollutants as much as possible.Discharge,alleviate environmental pressure.The article simplifies the nozzle structure,uses Fluent software to simulate and analyze the transient flow in the two-dimensional nozzle,and obtains the change of the internal flow field's velocity,pressure,and Mach number over time.The results show that when the fluid enters the nozzle,the velocity of the fluid increases with time,and the maximum velocity of the fluid at the throat of the nozzle is obtained.After that,when the throat velocity reaches subsonic speed,due to the internal fluctuations generated by the vortex,the velocity decreases.After the fluctuations disappear,the velocity slowly picks up,and finally the flow field reaches a stable state.