ASCENT Project 68: Combustor Wall Cooling Concepts for Dirt Mitigation

Sponsor: Federal Aviation Administration

Collaborator: Pratt & Whitney

One of the most critical issues related to the operation of a gas turbine in today’s world is the ingestion of dirt and other fine particles that lead to blockages of cooling holes and passages required for effectively cooling the walls of the combustion chamber. Because the need to fly in dirty environments is on the rise, the criticality of operations in dirty environments is increasing. Modern gas turbine engines typically employ a double-walled combustor liner with impingement and effusion cooling plates whereby impingement cooling enhances the backside internal cooling and effusion cooling creates a protective film of coolant along the external liner walls. Dirt accumulation on the internal surfaces severely diminish the heat transfer capability of these cooling designs. Additionally, dirt accumulates on the external surfaces of combustor panels.

The impact of this work is twofold: i) to develop a cooling design for combustor liners that is insensitive to “dirty” cooling air; and ii) to characterize the cooling performance and the impact that the cooling design has on the downstream turbine.