中心分级燃烧室同轴射流雾化机理与特性的数值研究

Numerical study on the mechanism and characteristics of coaxial jet atomization in central staged combustors

气液同轴射流雾化在先进航空发动机燃烧室中具有重要的应用。设计了同轴射流雾化简化模型,采用LES-VOF结合的方法,在2.7 MPa压力工况下对气液同轴射流雾化过程进行了数值模拟,探究了气流速度与供油压力扰动对射流雾化过程及特性的影响规律。研究发现:随着气流速度的增大,液体射流破碎加快,雾化索太尔平均直径显著减小,当气流速度增加至140 m/s后,其对液体射流雾化的影响减弱;供油压力扰动对射流雾化过程的影响较弱,当压力扰动幅值在供油压差的3%~5%之间时,液体射流的雾化效果改善。

The gas-liquid coaxial jet atomization has significant applications in advanced aero-engine combustors.A simplified model of coaxial jet atomization was designed,which adopted the VOF-LES(Volume of fluid-large eddy simulation)method to numerically simulate the atomization process of a gasliquid coaxial jet under the pressure condition of 2.7 MPa.The influences of airflow velocity and fuel supply pressure perturbation on the atomization process and characteristics of the liquid jet were investigated.It’s found that with the increase of airflow velocity,the liquid jet broke up more quickly,and the SMD(Sauter mean diameter)decreased significantly.However,the impact of airflow velocity on the atomization of the liquid jet diminished after it reached 140 m/s.The influence of fuel supply pressure perturbation on the jet atomization process was relatively weak.When the amplitude of pressure perturbation was between 3% and 5% of the fuel supply pressure difference,the atomization of the liquid jet was improved.