Abstract: Multi-hole film cooling of combustor liners is enhanced by providing clustered groups of cooling holes in areas of the liners that would otherwise experience a loss of cooling film effectiveness. The combustor liner is made up of a shell having first and second groups of cooling holes formed therein. The cooling holes of the second group are more closely spaced than the cooling holes of the first group. The second group of cooling holes is located on an area of the shell where the cooling film effectiveness is degraded. Preferred locations include a region of the shell that is subjected to swirl impingement and a spot immediately downstream of a large opening in the shell such as a dilution hole, a borescope hole or an igniter port hole.

Abstract: A combustor liner includes a wall having an outboard surface and an opposite inboard surface. A plurality of first holes are inclined through the wall in a multihole pattern to channel cooling fluid therethrough to form a cooling film layer along the inboard surface. A second hole extends perpendicularly through the wall within the multihole pattern to form a shadow along the inboard surface devoid of the first holes. A transition hole extends through the wall in the shadow at a greater inclination than the first holes for cooling the wall at the shadow.