燃烧室涡流器流量系数与阻力系数的试验分析

航空喷气发动机燃烧室中广泛采用叶片涡流器来控制火焰筒的一次空气流量,并建立强回流区。 本文通过总结一组具有不同叶片安装角、叶片数及通道截面积的直叶片涡流器的试验结果,提出了一套涡流器的流量特性与阻力特性曲线,并建立了涡流器的阻力系数与涡流数,叶片安装角、涡流器的流量系数与阻力系数之间的关联式。

EXPERIMENTAL STUDY ON DISCHARGE AND LOSS COEFFICIENTS OF COMBUSTOR SWIRLERS

The blade-type swirlers have been used in many air engine combustors to control the primary airflow of flame tube and establish a strong recirculation zone. The losses produced by the swirler depend on stagger angle, pitch/chord ratio and passage area of blades.Some test results of the swirlers with different stagger angles, numbers of blades and flow areas are presented. A set of discharge characteristics and relations between loss coefficient and swirl number, stagger angle or blade number are provided. In addition, the correlation of loss coefficient to discharge coefficient of blade-type swirlers has been established. It is found out that the discharge coefficient varies from 0.6 to 0.9 for swirlers with different stagger angles. The correlation ψ=31.0（1.53s- 1） indicates that the selection of swirl number must retain the loss coefficient at an acceptable level （aerodynamically）.It can be seen from the test results that the blade loss is evidently smaller than the secondary expansion loss for a given combustor swirler. The value of the blade loss is about 18 percent of the total loss for a straight blade swirler with stagger angle varying from 68° to 70°.The tests have also proved that the twisted blade swirler is superior to the straight one from the aerodynamic point of view. But its manufacture is more complicated. Therefore, the straight blade swirlers （with stagger angle ≥45°） have been used in a large number of combustors.