旋流杯矩阵下游冷态流场特征分析

Analysis of cold flow field downstream of swirl cup array

中文关键词: 航空发动机燃烧室  旋流杯矩阵  回流区  数值模拟

英文关键词: Aero-engine combustor  Swirl-cup array  Recirculation zone  Numerical simulation

中文摘要:

      基于分级贫油直射燃烧概念的多点喷雾燃烧室在降低航空发动机氮氧化物排放方面显示出极大的潜力，在传统航空发动机燃烧室模型的基础上构建了相邻旋流杯旋转方向相同（顺转）和相反（逆转）两种3*3旋流杯矩阵，数值计算采用可实现k-ε湍流模型，对比分析了旋流杯矩阵下游流场特性。结果表明，对于逆转旋流杯矩阵，部分旋流杯下游回流区相互靠近，而且回流区的长度与回流速度均大于顺转旋流杯矩阵情况。这有利于维持火焰稳定，但燃烧情况下气流在高温环境中滞留时间增加，不利于降低氮氧化物排量。对于顺转和逆转两种旋流杯矩阵，下游回流区边缘处湍流动能最大值与湍流动能分布相似。

英文摘要:

      The multiplex fuel injector combustor based on the concept of the staged lean direct injection was proved good for the emission reduction. The builds co-rotation and counter-rotation 3*3 swirl-cup arrays based on the traditional aeroengine combustion chamber model. The numerical calculation uses the k-ε turbulence model to compare the two flow field downstream.The results show that part of the recirculation zones of counter-rotation swirl cup array get close to each other, and the length and the velocity of recirculation zones for the counter-rotation swirl cup array are both greater than those of the co-rotation swirl cup array. This is beneficial to maintain flame stability, but under combustion conditions the residence time of the gas flow in the high temperature zone increases, which is not conducive to reducing the NOx emission. For the both swirl-cup arrays, the maximum turbulent kinetic energy and distribution of turbulent kinetic energy at the edges of the downstream recirculation zones are similar.