Numerical evaluation on single-row trenched-hole film cooling performances on turbine guide vane under engine-representative conditions

Abstract

A numerical investigation is performed to study the effects of transverse trenches on the film cooling performances of single row film cooling holes on the turbine guide vane, under the engine-representative conditions. Two trenches are investigated in the current study, including a conventional straight trench and a novel serrated trench, both having the same slot width of 2.5d and depth of 0.75d. With the presence of trenches, the kidney vortices are effectively destroyed at the suction side, replaced by a pair of secondary vortices originating from the edge of trench slot, with a sense of rotation opposite to the kidney-vortex pair. However, at the pressure side, the kidney vortices remain clearly in the trenched-hole cases. The roles of trenched-hole on the film cooling enhancement behave more pronounced on the pressure surface when compared to the respective one on the suction surface. On the pressure surface, the serrated trench displays a more obvious role in the film cooling enhancement when compared to the straight trench. Combined with the effects of trenched-hole on the enthalpy loss coefficient, it is suggested that the trenches are more reasonably used on the pressure surface.

Additional information

Funding

The authors gratefully acknowledge the financial support for this project from the National Natural Science Foundation of China (grant No: U1508212, 51706097).