摘要
提出采用高负荷设计以减少叶片数的方法,增大圆盘直径而减小泄漏面积;结合叶片进行后加载改型措施以减小由于高负荷设计所增加的二次流损失.对定几何涡轮、仅有驱动轴的变几何涡轮与带圆盘型冠的变几何涡轮的流场进行三维数值模拟计算,分析了3种涡轮性能的优劣.结果表明:大间隙尺度下了间隙泄漏涡强度较大,并与通道涡相互融合,从而增大了泄漏损失区域,增加了泄漏损失;而在涡轮叶片由于高负荷设计会增加了主流区的二次流损失.该方法可以有效地减小周向泄漏面积,极大地抑制由大间隙尺度所导致的间隙泄漏涡与通道涡的相互融合,减小泄漏损失.而通过后加载改型的措施,抑制了主流区的通道涡的发展趋势,减小了二次流损失.这两种措施结合后的变几何涡轮具有较高的全工况性能.
The high load design was adopted to reduce blades to increase diameter of disc while reducing the circumferential leakage area. And aft-loaded cascades were employed to retrofit design to minimize the secondary flow loss brought about by high load design. For the fixed geometry turbine, only the flow field of the variable geometry turbine of driving ax- is and disc type crown variable geometry turbine was numerically calculated. Three kinds of turbine performance under all conditions were analyzed. Result shows that, under the big clearance, intensity of the clearance leakage vortex was big. If merged with the passage vortex, the leakage loss became bigger. The high load design brought the secondary flow loss. The method reduced the circumferential leakage area, restraining greatly the merges between the leakage flow and the secondary flow to reduce the clearance leakage loss. High load design can effectively restrain the development trend of passage vortex, thereby reducing the secondary flow loss. With two measures, the variable geometry turbine has high perform- ance under overall conditions.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2017年第3期558-567,共10页
Journal of Aerospace Power
基金
国家自然科学基金(51406039)
中央高校基本科研业务费专项资金(HEUCF150302)
关键词
变几何涡轮
大子午扩张
圆盘型冠
间隙泄漏
后加载叶型
气动性能
variable geometry turbine
clearance leakage loss
aft large meridional expansion
disc type crown
loaded blade profile
aerodynamic performance
