Patent ID: 8024933

Claim:
A wall element of a gas turbine engine combustor, the wall element comprising: an inner, in use, hot surface; an outer, in use, cooler surface, with respect to the gas turbine engine combustor, wherein the wall structure having a downstream edge such that a coolant flow over the outer cooler, in use, surface exits the wall element at the downstream edge; and a plurality of projections being provided on the outer surface to facilitate heat transfer to the coolant flow during use, wherein a portion of said plurality of projections being constructed and arranged to direct more coolant flow leaving the downstream edge at a hot-spot on an adjacent tile during use than the remainder of the adjacent tile to reduce the thermal gradient across the adjacent tile, and wherein said plurality of projections are arranged in a first pattern and a second pattern, said first pattern comprising a staggered array of projections and said second pattern comprising said portion of said plurality of projections, and wherein at least some of the projections in the second pattern comprise a plurality of discrete pedestals, and wherein a space between adjacent pedestals, within the plurality of discrete pedestals, is less than the corresponding dimension of either adjacent pedestal.