Computational study of a new scheme for a film-cooling hole on convex surface of turbine blades

An investigation on a heart-shaped film cooling hole is performed for one row, two staggered rows, and three staggered rows on a convex surface. The results are compared with those obtained from a simple cylinder hole as a baseline. Three-dimensional computational study for two heart-shaped holes of two crown angles, φ = 60° and φ = 90°, is conducted to ascertain adiabatic film cooling effectiveness to validate whether a heart-shaped cooling hole mitigates the vortexes responsible for the lift-off phenomenon in conventional simple cylinder hole. This paper also attempts to show that the staggered arrangement of a heart-shaped hole provides higher cooling performance. The result reveals that a heart-shaped hole highly mitigates the vortexes, thereby providing more coolant-surface attachment. The results reflect the tremendous increment in centerline and lateral adiabatic film cooling effectiveness for both crown angles, φ = 60° and φ = 90°. The heart-shaped hole of crown angle φ = 60° shows higher centerline effectiveness compared with that of the heart-shaped hole crown angle of φ = 90°. The latter provides higher lateral effectiveness. The relatively small volume and high effectiveness of the heart-shaped cooling hole is important and promising for the aero engine industry.