本征正交分解法对正十二烷喷雾射流的解析

应用大涡模拟方法对航空煤油单组分替代燃料正十二烷冷态喷雾现象进行模拟计算，探究喷雾射流中的多物理场耦合现象。从宏观层面分析燃油破碎蒸发及油气混合过程，发现流场涡团在其中起着重要的作用。运用本征正交分解方法对正十二烷射流质量分数场和涡量场数据库进行加工，从“微观”层面深入探究两者的联系。结果表明:正十二烷质量分数场喷雾结构与射流涡量场涡团结构存在显著的空间分布相关性，反应出两者结构演变具有重要关联特征。湍流脉动致使涡团尺度发生变化，从而影响燃油破碎蒸发，最终使得喷雾不同尺度结构分布形态发生改变。 

Analysis of n-dodecane spray jet by proper orthogonal decomposition

Large eddy simulation was used to calculate the cold spray phenomenon of single component alternative fuel n-dodecane for aviation kerosene，and to explore the coupling phenomenon of multiple physical fields in spray jets.The process of fuel breaking，evaporation and oil-gas mixing was analyzed from the macro level，and it was found that the flow field vortices played an important role in the process.The data base of mass fraction field and vorticity field of n-dodecane jet flow was processed by the proper orthogonal decomposition，and the relationship between them was explored from the micro level.The results showed that there was a significant spatial distribution correlation between the n-dodecane mass fraction field spray structure and the jet flow vorticity field vortex structure，reflecting that the evolution of two structures had important correlation characteristics.The turbulence fluctuation resulted in the change of the vortex scale，which affected the breakup and evaporation of the fuel，and finally changed the distribution morphologies of different scale structures of spray.