高压涡轮导叶弯曲对气动性能及动叶激振力的影响

The Effect of Bowed Vanes on High Pressure Turbine Aerodynamic Performance and Blade Vibration

对某双级高压涡轮一级导叶进行了正弯设计,一方面为了提升气动性能,另一方面为了减小下游动叶的激振力。采用商业软件CFX对基准方案和弯曲方案进行了全三维粘性定常和非定常计算,结果表明:导叶采用正弯设计,端区损失明显减少,叶中损失略有增大,导叶总损失减少;同时导叶弯曲还改善了下游动叶的进气条件,减小了动叶损失,最终使得高压涡轮效率提高0.1个百分点。为评估导叶弯曲对动叶激振力的影响,以气动非定常计算的叶片表面压力为输入,采用ANSYS对弯曲前后一动叶身激振力进行了强度分析,分析结果表明一导采用弯叶片,改变了导叶尾迹形状同时使得动叶进口流场更均匀,带来一动激振力下降10%~15%,有利于强度设计。

In order to improve the aerodymic performance of HPT and reduce the vibration of downstream Blade,a bowed vane was adopted in a two stage high turbine.Steady and unsteady aerodymic numerical computation was excuted on both the straight and the bowed design by using 3D viscous CFD simulation.The result show that by using bowed vane the loss at hub and shroud of the vane passage was decreased obviously,although the loss at middle span was slightly increased,the total loss of the vane reduced.Meanwhile,the bowed vane could also refine the inlet flow of the downstream blade passage,finally,the HPT aerodymic efficiency was enhanced by 0.1 percent by using bowed vane.An unsteady numerical simulation and a structure analysis were carried out to evaluate the effect of bowed vane on the vibration of downstream blade,unsteady result indicates that the wake shape of the upstream vane was changed while using bowed vane and flow fields at the outlet of the vane also become more uniform,the structure analysis result also shows that the vibration of the blade was reduced by 10~15 percent.