超紧凑涡轮过渡段数值模拟研究

Numerical Study of Aggressive Intermediate Turbine Ducts

采用数值模拟方法对超紧凑涡轮过渡段进行了研究。通过对比6个不同超紧凑过渡段模型模拟结果,分析了过渡段内部流动基本特征,探讨了长度和支板对超紧凑过渡段内部流动损失的影响规律。结果表明,对于超紧凑过渡段而言,长度越短,其流动损失越大;而且进一步缩短长度的流动损失"成本"越大。支板的引入改变了流通面积,进而影响过渡段内部压力分布;并与上下游叶片相互作用,改变过渡段内部流动分离及损失状况。整体而言,支板使得过渡段流动损失明显增大且过渡段长度越短,支板带来的额外流动损失越大。

In the present work , aggressive intermediate turbine ducts （ITD） were studied by numerical simula-tion method. By comparing the simulation results of six dif fe re nt duct mod els, basic flow characterestics in the ducts were analyzed, also with the in flue nce of duct length and stmt on flow losses. The results show that the shor-ter the length of ITD , the greater the flow losses in the duct. Fur the rmo re,as the duct becomes sho r te r, the “ cost” for further shorten the length increased, w h ich indicated via flow losses. Also in ITD , stmt changes the flow area of the duct, which affects the pressure distribution in the duct. At the same time , stmt changes the separation distri-bution and flow losses in the duct by its interact ion with blades at both upstream and downstream. Overall, with the influence of stmt, flow losses in ITD increased significantly and the shorter the duct, the greater the ad ditional flow losses induced by strut.