出口宽高比及旋流角对双涵道S弯喷管温度分布的影响

Effect of aspect ratio and swirl angle on temperature distribution of double serpentine nozzle for turbofan

采用数值方法研究了出口宽高比及旋流角对基于真实排气混合器构型的双涵道S弯喷管内/外流场温度分布的影响。结果显示:在圆转方弯曲构型的作用下,波瓣混合器及尾锥诱导产生的流向涡在第二弯通道及等直段内部卷吸着热流冲击S弯喷管壁面形成“热斑”。在完全遮挡高温部件准则的约束下,随着出口宽高比的增加,S弯喷管壁面的“热斑”温度先增大后减小,当出口宽高比为5时,壁面“热斑”温度最高,相比喷管基准模型增加1.3%。而出口宽高比的增加导致喷管出口下游尾焰的长度逐渐缩短。随着旋流角的增加,喷管下壁面的“热斑”温度先减小后增大,旋流角为10°时达到最小值,壁面温度峰值相比无旋流角工况降低15.9%。而旋流角增加导致喷管出口下游尾焰的宽度逐渐增大,长度逐渐缩短。

The effects of the aspect ratio and the swirl angle on the temperature distributions of the internal flow and external jet fields of the double serpentine nozzle with real lobed mixer configuration were numerically investigated. The results indicated that, under the action of the bending configuration with the circular-to-rectangular transition,the streamwise vortices induced by the lobed mixer and the tail cone entrained the core flow to impact the nozzle wall, and the“hot streak”was formed at the wall surface of the second S passage and the linear section. Under the constraint of the criterion of completely shielding high temperature components,the temperature of the“hot streak”on the nozzle wall first increased and then decreased as the aspect ratio raised gradually. The value of the temperature peak of the“hot streak”was up to maximum when the aspect ratio was 5. It rose by 1. 3% compared with that in the benchmark nozzle model. The plume core region downstream the nozzle exit was shortened effectively with the increment of the aspect ratio. The temperature of the“hot streak”on the nozzle lower wall first decreased and then increased as the swirl angle raised sustainedly. The value of the temperature peak of the“hot streak”was up to minimum when the swirl angle was 10°. It dropped by 15. 9% compared with that under the condition of 0° swirl angle. The lateral width of the plume core region downstream the nozzle exit was enlarged notably while its axial length was shortened effectively with the increment of the swirl angle.