A Method for Predicting the Mixing Loss of Main Flow and Double-Row Cooling Flow at Off-Design Condition

Wei Jia ； Han Dong Mu

《Journal of Aeronautics, Astronautics and Aviation》 55卷3期 Vol.55 No.3 (2023/09) Pp. 347-357

https://doi.org/10.6125/JoAAA.202309_55(3).05

摘要

In order to predict the mixing loss between the main flow and cooling flow at off-design condition, numerical simulation of turbine cascade with double-row film cooling holes was performed. Results showed that the mixing loss near the blade suction side is significantly higher than that of the pressure side. For the cooling flow from the blade pressure side, the effect of adjacent cooling flows on the mixing loss can be treated separately. However, for the cooling flows from the blade suction side, the maximum deviation between the predicted and numerical simulation result is about 7% for upstream cooling flow with high blowing ratio while greater than 10% for upstream cooling flow with low blowing ratio. The entrainment of the low energy flow in the boundary layer into the upstream cooling flow results in a higher mixing loss between the adjacent cooling flows. It is demonstrated that the interaction between the adjacent cooling flows needs to be considered in certain cases. Based on the typical cooling flow patterns, a method for predicting the mixing loss was proposed and validated. The maximum deviation between the predicted result and numerical simulation result is less than 6% for turbine stage with multi-row cooling flows at off-design condition.

關鍵字

Mixing loss ； Cooling flow pattern ； Blowing ratio ； Kinetic energy ratio ； Off-design condition

參考文獻

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