Influence of Pin fin Arrangement on the Film Cooling Characteristics of Mesh-Fed Slot Configuration

The at plate experimental investigations have been conducted to study the _lm cooling characteristics of mesh-fed slot configuration. The film cooling effectiveness and heat transfer coefficient distribution downstream the slot were measured by the transient thermal liquid crystal technique. The film cooling effectiveness of the mesh-fed slot was compared with the cylindrical hole in the condition of same pressure ratio. Meanwhile, the effect of the in-wall pin-fin arrangement on the film cooing characteristics of the mesh-fed slot was also investigated. The blowing ratio of the mesh-fed slot ranged form 0.26 to 1.25. The results show that the film cooling effectiveness laterally distribution of the mesh-fed slot is more uniform than the cylindrical hole, the jet lift-off didn't appear in the mesh-fed slot configuration when the blowing ratio increased. The counter-rotating vorticities are induced by the appendence of pin-fins and inclined plane downstream the slot. They make the film cooling effectiveness higher in the region of the downstream of the last row of pin-fin. The in-line pin-fin arrangement provides more uniform film cooling effectiveness distribution downstream the slot. At high blowing ratio, the laterally averaged film cooling effectiveness of the in-line configuration is 23%-84% higher than the staggered configuration, and the ratio of heat transfer coefficient is 11% higher. When the blowing ratio is less than 1, the discharge coefficient of in-line configuration is higher; and when the blowing ratio is more than 1, the discharge coefficient of staggered configuration is higher.