不同进口雷诺数下双旋流杯下游回流区特征

Characteristics of the recirculation zone downstream a dual-swirl cup at varied inlet Reynolds numbers

为了分析旋流杯下游流场结构对航空燃气轮机燃烧室性能影响的作用,利用PIV(激光粒子测速仪)技术,在常温常压下对双旋流杯下游冷态流场进行测试,研究进口雷诺数对双旋流杯下游回流区的影响.试验结果表明:当进口雷诺数较低时,下游流场结构为收扩型;当进口雷诺数增大到25 000后,流场结构变为扩张型;之后继续增加进口雷诺数,回流区流场结构不再改变,但回流区内的无量纲回流速度会随之增加.

To analyze the role of the flow structure downstream the swirl cup on the per- formance of aero gas turbine combustors, PIV （particle image velocimetry） was used to measure the non-reacting flow field downstream a dual-swirl cup under ambient pressure and temperature, and the effect of the inlet Reynolds number on the recirculation zone down- stream a dual-swirl cup was studied. The experimental results indicate that the flow struc- ture downstream is a converge-diverge type when the inlet Reynolds number is low. As the inlet Reynolds number increases to 25000, the flow structure turns to a diverge type. Then the flow structure of recirculation zone remains unchanged with increasing inlet Reynolds number, but the normalized velocities in the recirculation zone would increase accordingly.