Clogging-Resistant Combustion Liner

The Army uses gas turbine engines in a variety of propulsion systems including helicopters and ground vehicles. These systems often operate in regions where sand and dust ingestion is problematic. A typical combustion liner in a gas turbine engine involves a thin metal structure with an array of round holes for effusion cooling. If sand and dust are ingested into the engine, it can clog cooling holes. If combustion liner holes clog, engine performance and durability are degraded. This results in potentially time consuming and expensive maintenance, or in extreme cases, engine failure. We propose to develop a combustor liner that has reduced clogging sensitivity relative to a conventional design. Our design uses the same metal architecture as a conventional liner, and is compatible with thermal barrier coatings, but uses cooling holes that are less sensitive to clogging and will therefore extend maintenance intervals and the engine life cycle. In Phase I, we will demonstrate our approach through computational analysis and direct experimentation using sub-scale test coupons. We will also demonstrate the capability to fabricate the proposed cooling holes. In Phase II, we will further develop and optimize our liner concept, and will fabricate and test a full-scale liner.