喷嘴出口长度对喷嘴雾化特性影响的数值模拟

Numerical Simulation of Influence of Nozzle Outlet Length on Atomization Characteristics

在航空发动机中,喷嘴等值段长度对雾化特性影响较大。通过数值模拟,研究喷嘴出口等值段长度对离心式喷嘴雾化特性的影响。在喷嘴出口等值段长度的基础上,分别加设1mm、1.5mm、2 mm、2.5mm,应用Fluent软件进行数值模拟,分析不同喷嘴出口等值段长度的离心式喷嘴的雾化特性。分析结果表明,在增大喷嘴出口等值段长度的过程中,液膜厚度先减小后增大。当加设长度为2mm时,液膜厚度达到最小,雾化锥角大小合适,雾化特性较好。将数值模拟结果与经验公式计算结果进行对比,发现两者相差较小,并且变化趋势一致,说明数值模拟结果与经验公式计算结果相符,验证了数值模拟结果的可靠性。所做数值模拟研究对离心式喷嘴出口形状的设计具有一定的指导意义。

In the aero engine,nozzle equivalent segment length has a great influence on atomization characteristics.Through numerical simulation,the influence of nozzle outlet equivalent segment length on the atomization characteristics of centrifugal nozzle was studied.On the basis of the nozzle outlet equivalent segment length,1 mm,1.5 mm,2 mm and 2.5 mm were added respectively,and the numerical simulation was carried out by using Fluent software to analyze the atomization characteristics of centrifugal nozzle with different nozzle outlet equivalent segment length.The analysis results show that in the process of increasing the nozzle outlet equivalent segment length,the thickness of the liquid film first decreases and then increases.When the added length is 2 mm,the thickness of the liquid film reaches the minimum,the size of the atomization cone angle is suitable,and the atomization characteristics are better.The numerical simulation results and the empirical formula calculation results were compared,and it is found that the difference between the two is small and the change trend is consistent,indicating that the numerical simulation results are consistent with the empirical formula calculation results,and the reliability of the numerical simulation results was verified.The numerical simulation research has certain guiding significance for the design of the outlet shape of the centrifugal nozzle.