The Aerodynamic Optimaldesign Of Subsonic Stages In Heavy Duty Gas Trubine

A two stage compressor of a heavy duty gas turbine which is subsonic is studied in this paper. The software NUMECA is used to help us analysis the 3D flow field of original stator. Based on the study of the original stator, the End-bend blade, End-bend & bowed blade and Match optimal design technology are used to improve the aerodynamic performance and extend the stable working range of the compressor.In this paper, the original stator is studied. By analyzing the original stator, it is found that the corner separation flow result in high loss of the stator and may lead to stall of the compressor. Further analysis shows that the high lever inlet incidence angle may leads to the corner flow separation. As a result, some measures are taken to reduce the high level inlet incidence angle in the corner.End-bend blade is proved to be an efficient means which can reduce the incidence angle by matching the flow angle in the corner. Different End-bend plans are used and the 7% plan is proved to be the best. The comparison of original stator and the 7% End-bend stator is carried out to check its impact on the aerodynamic performance and stable working range. The result shows that the 7% End-bend stator highly improves the efficiency and pressure ratio on the design and stall point but be a litter harmful to the chock point, also the stall margin and stable working range are extended. Another optimal design technology named"End-bend & bowed blade"is carried out. Based on the End-bend blade, the bowed blade is used to check its influence on the End-bend blade. End-bend blade combines with positive bowed can further strengthen the positive bow effect of the blade which is benefit for the separation control. On the contrary, End-bend & negative bowed blade works on the other side.Based on the End-bend optimal design, studies on the flow angle match and character analysis is performed between Stg14 and Stg15. Compared with the original stator, the End-bend optimal design can significantly improve the angle match situation on the shroud region, few effects on the mean region, do little harm to the hub region. Another optimal solution named Match optimal design is put out based on the angel match analysis which is expected to improve the angle match situation on the hub area. Comparison between original stator, End-bend optimal design and Match optimal design show that the Match optimal design improves the hub and shroud angle match situation and do few effects on the mean region. The character of two stage compressor shows that the match optimal design improves the efficiency and pressure ratio on the design and stall point while reduces on the chock point.