DEVELOP SAND-PLUGGING RESISTANT METALLIC COMBUSTOR LINERS

Gas turbine engines that operate in regions with high concentrations of dust/sand are prone to suffer accelerated deterioration due to erosion, plugging, melting, deposition, coating degradation and consequential damage. Dust/sand ingested into the inlet of gas turbine engines is pulverized by the turbomachinery to ultra-fine size, typically less than 10 micrometers. The ultra-fine dust is difficult to extract (i.e. through particle separators or barriers) from the engine flowpath and is readily transported into the primary and secondary gas path flows. The combustor module is particularly susceptible to deposition of ultra-fine sand in cooling passages reducing useful life by as much as 80%. The advent of additive manufacturing (AM) provides the opportunity to develop specifically tailored cooling hole geometries that can resist or tolerate sand and thereby reduce the deposition and consequential plugging. Modern direct metal laser sintering (DMLS) machines offer the geometric precision, adequate build times and sufficient build volumes to fabricate entire combustor liners with appropriate high-temperature (Nickel based) alloys. This research aims to utilize computational fluid dynamics (CFD) and AM simulation tools to optimize cooling hole geometry in order to substantially reduce clogging of cooling passages while maintaining their cooling effectiveness.