旋流杯近场液雾SMD的空间分布模型

旋流杯液雾的空间分布特性对航空发动机燃烧室燃烧性能至关重要。基于旋流杯燃油雾化的物理过程及其近场液雾索太尔平均直径(SMD)空间分布呈"双峰"或"三峰"分布的基本特点,建立了旋流杯近场液雾SMD空间分布的半经验模型。该模型将旋流杯近场液雾分为中心区和边界区,其中中心区液雾采用离心喷嘴与内旋流的混合型雾化模型,边界区液雾采用文氏管液膜的气动雾化模型,同时将液雾SMD及SMD空间分布与正态分布函数相结合。根据空气压降不同,分别对压力雾化主导及气动雾化主导两种形式的旋流杯液雾SMD空间分布模型进行了验证,并对供液压力及空气压降的影响规律进行了预测分析,预测结果表明:随着供液压力和空气压降的增大,旋流杯液雾SMD呈现整体降低的趋势。

Model of spatial SMD distribution of spray at the near-field of swirl cup

A semi-empirical model of spatial SMD distribution at the near-field of swirl cup was proposed based on the physical process of swirl cup atomization and the characteristics of spatial Sauter mean diameter (SMD) distribution. The swirl cup spray at the near-field was divided into central zone and border zone, the hybrid atomization model of pressure swirl with primary air blast atomizer was used for the central zone, and the prefilming airblast atomization model of Ventruri tube was used for the border zone spray. The SMD and SMD spatial distributions of the spray were combined with Gaussian distribution simultaneously. According to the difference of air pressure drop, two types of semi-empirical models: pressure swirl atomization dominated model and airblast atomization dominated model, were validated respectively. Furthermore, the influences of liquid pressure and air pressure drop on the spatial SMD distribution were predicted and analyzed. Pediction results show that: the SMD decrease with the increase of liquid pressure or air pressure drop.