In order to explore the effect of blowing ratio on film cooling over a convex surface, the present study adopts the transient liquid crystal thermography for the film cooling
measurement on a straight circular hole configuration. The test piece has a strength of
curvature (2r/D) of 92.5, pitch to diameter ratio
(P/D) of 3 and streamwise injection
angle (γ) of 35∘ All measurements were conducted under the mainstream Reynolds
number (Red) of 1700 with turbulence intensity (Tu) of 3.8%, and the density ratio between coolant and mainstream (ρc/ρm) is 0.98. In current study, the effect of blowing
ratio (M) on film cooling performance is investigated by varying the range of blowing
ratio from 0.5 to 2.0. Two transient tests of different injection flow temperature were
conducted to obtain both detailed heat transfer coefficient and film cooling effectiveness
distributions of measured region. The present measured results show that both the
spanwise averaged heat transfer coefficient and film cooling effectiveness increase with
decreased blowing ratio.
