LAUSR

At three blowing ratios (M = 0.5, 1, and 1.5), film cooling effectiveness on plain wall surface with designed contoured crater cooling hole was numerically investigated. With variable crater depth (0.4D≤d≤2.7D) and crater expansion angle (18°–30°), the optimal crater hole was determined and then combined with SDBD plasma actuation further. Effects of SDBD plasma actuation frequency (0≤Dθ≤11.25) and actuation strength (0≤Ds≤100) were analyzed, and the cases of the conventional cylindrical holes (i.e. baseline cases) were also conducted for comparison. The results showed that the wall film cooling effectiveness gradually rises with increased crater depth and remains stable with crater depth up to 2.3D. Compared to the baseline case, the laterally averaged wall film cooling effectiveness of the contoured crater hole of d = 2.3D is increased by over 55%, 500%, and 700% near the hole (X/D<3), and nearly 45%, 300%, and over 850% downstream region (33) at M =1.