中心线偏置对隔离段性能的影响研究

Influence of deflected center-line on performance of isolator

在隔离段入口马赫数2.0条件下对二维中心线偏置隔离段流场进行了数值计算,并与直隔离段结果进行对比,分析了两种偏置方式对隔离段流场结构及性能特征的影响,重点研究了隔离段的总压恢复性能和抗反压性能,并考察了管道扩张角对结果的影响。结果表明,出口反压较低时,直隔离段总压恢复性能优于折线隔离段;反压较高时,两者总压恢复性能大致相当。S弯隔离段总压恢复性能介于两者之间。对相同扩张比隔离段而言,直隔离段抗反压性能最强,折线隔离段次之,S弯隔离段最差。扩张隔离段的抗反压性能增强,但在同一反压条件下的总压恢复性能下降。

The flow field in two-dimension deflected center-line isolator was numerically computed at 2.0 Mach number at the inlet of the isolator and the result was compared with that of straight isolator. The effects of the two-types of the deflected modes on flow field structure and performance of the isolator were analyzed. More attention was paid to the research of total-pressure recovery and back pressure resistance performances. The effects of expanded angle of pipe on the result were also taken into consideration. The result indicates that the straight isolator has better total-pressure recovery performance than the turning isolator when the back-pressure at outlet is low, and the total pressure recovery performance of the two modes is almost the same when the back-pressure is higher. The lotal-pressure recovery performance of the S-shape isolator falls in between of the two modes. As for the isolators with same expanded angle, the straight isolator has the best pressure rcsistance performance, the turning isolator takes second place, and the S-shape isolator is the worst. In addition, the expanded isolator has better total-pressure recovery performance, but its total-pressure recovery performance declines under the condition of the same back-pressure.