COMPARISON OF DIRT DEPOSITION ON DOUBLE-WALLED COMBUSTOR LINER GEOMETRIES

Gas turbine engines are frequently subjected to particle laden flows in which dirt and sand are ingested into the hot section. The particles enter internal cooling channels where they deposit and block cooling features, creating increased heat transfer, reduced flows, and diminished cooling performance. This study investigates geometries with the intention of mitigating dirt effects on cooling for double-walled combustor liners that use impingement and effusion cooling. Dirt particulate was injected into several double-walled coupons at room temperature using two feed modes: slug and continuous. Slug feed tests used controlled bursts of dirt whereas continuous feed provided a steady stream of dirt. Computational studies were also conducted to investigate internal flow fields between the impingement and effusion plates. The best performing geometry that was tested in terms of the lowest measured dirt capture had pins and cones extruded from the cold-side of the effusion plate. The flow parameter was found to scale the dirt capture with higher capture efficiency at higher flow parameters.