不同进气状态对矩形大S弯扩压器流动特性的影响

通过亚音扩压器内壁面流谱图、有关截面的总压恢复分布图、速度矢量图以及各壁面沿程静压恢复系数分布分析对比了四种进气状态下矩形大Ｓ弯扩压器流动特性。试验表明不同进气状态对矩形大Ｓ弯扩压器性能有很大影响，其中均匀核心流进气条件下的流动代表了大Ｓ弯扩压器流动的一般特征，其出口平均总压恢复系数最高，周向总压畸变指数不大，旋流很弱。研究腹部或两侧进气道地面起飞进气状态下矩形大Ｓ弯扩压器的流动特性更具有实际意义。试验表明其出口平均总压恢复系数较低，周向总压畸变指数较大，旋流较强且很不规则。

THE INFLUENCE OF INCOMING FLOW CONDITIONS ON FLOW CHARACTERISTICS IN A LARGE S-BEND RECTANGULAR DIFFUSER

low characteristics in a large s-bend rectangular diffuser are analysed and compared under four through incoming flow conditions flow visulization on the walls of the diffuser, distribution plots of total pressure recovery, plots of velocity vector and distribution of static pressure recovery along the walls. As indicated in experiments, the flow characteristics are influnced greatly by incoming flow conditions, of which the incoming flow condition with uniform core velocity represents the common characteristics of the large s-ben4 diffuser, such as highest average total pressure recovery, smaller circumferential total pressure distortion and weaker secondary flow. The investigation under static condition on flow characteristics in the large S-bend rectangar diffuser with side inlet is more pratically significante. Test results show lower exit average total pressure recovery, larger circumferential total pressure distortion and stronger and more irregular secondary flow.