中心突扩燃烧室压强振荡试验研究

Experimental investigation of pressure oscillations in centeral-dump combustor

对两种结构中心突扩燃烧室在不同入口速度条件下的压强振荡问题进行了气体冷流试验。试验结果表明,随入口速度的增大,压强整体脉动幅值也逐渐增大,脉动主频也有增大的趋势,但不是严格随入口速度的增大而增大。在速度比较低的情况下,单一主频的振荡起主要作用,振荡幅值随速度的增大而增大,当振幅增加到一定值时,该主频的振荡趋于饱和,而次频振荡的作用逐渐增大。对于同一入口速度,燃烧室不同位置,压强脉动的幅值不同,进气道流场的压强脉动幅值最大,而回流区流场的压强脉动幅值最小。

Cold flow pressure oscillation experiments were performed on condition of different inlet velocity in two kinds of central-dump combustor. The expererimental result showed that the total amplitude is increasing as augmentation of inlet velocity. The primary frequency also has a tendency to increase , but it is not monotonously increase with inlet velocity. On the condition of low velocity, primary frequency oscillation dominates flow field, its amplitude increase with ve- locity. As amplitude adds up to a certain value, the primary frequency oscillation tends to satura- tion and the secondary frequency oscillation tends to enhancement. On a certain inlet velocity, pressure oscillation amplitude is different as measure point. The maximal amplitude is obtained in inlet district, and the minimal in recirculation district .