大叶尖间隙下叶栅性能数值模拟

利用NUMECA软件对某线性叶栅的三维流场进行了数值模拟,对比研究了小叶尖间隙和大叶尖间隙时叶尖泄漏涡流的形成和发展,探讨了叶尖间隙大小对叶栅流场和气动性能的影响。研究表明,随着叶尖间隙的增大,叶尖泄漏射流发展成为叶尖泄漏涡,涡流范围不断增大,涡流强度增大趋缓,涡流使得气流偏转减小。从小间隙逐渐增大到大间隙,总压损失与叶片载荷均增大,而在大叶尖间隙时,总压损失增加并不显著,叶片载荷增大趋缓。其结论为进一步揭示叶尖间隙涡流的流动机理以及工业燃气轮机的优化设计提供了参考。

Numerical Simulation on Liner Cascade with Large Tip Clearance

In this paper ,the three-dimensional flow of a liner cascade has been numerical simulated by u-sing the commercial software Numeca .To investigate the formation and development of the leakage vortex and the influence of the tip clearance size in the aerodynamic characteristics and flow field of the cas-cade ,the calculation of the cascade in different tip clearance , such as small tip clearance and large tip clearance has been done .The result showed that while the tip clearance increased ,the jet gradually devel-oped into a vortex ,and the scope of the vortex increased ,but the intensity of the vortex didn′t increased notably .Meanwhile ,the deflection of the flow caused by the vortex decreased .When the tip clearance size increased from small one to large one ,both the total pressure loss and the blade force increased remark-ably.However,within the large tip clearance,the total pressure loss didn′t increase clearly and the in-crease of the blade force tended to be slow .These results might provide significant inference to the study of leakage vortex and the design of industrial gas turbines .