Improved Bearing Compartment Sealing for Gas Turbine Engines

Carbon seals generlly used for bearing compartments will incrasingly become unsuitable for future gas turbine engines with higher buffer air temperatures, higher pressur and rotor surface speeds.Phase I effort will focus on a synergistic approach including advanced materials and design.Three materials including a (Ti,Mo)(C,N) cermet, B-C composite and a current high temperature grade carbon MAT-1200 will be characterized for wear, oxidation resistance, impact strength and corrosion resistance in bearing oil. Both (Ti,Mo)(C,N)cermet and B-C composite have a much lower dry running wear rate, superior thermal stability and impact resistance compared to carbon.Advanced materials will be complemented with two non-contacting film riding design concepts; one based on hydrosttic arch-bound and another radial groove circumferential seal to furher minimize wear and degradation of leakage performance. Based on Phase I results, Phase II will focus on further design optimization using a comprehensive design code and performance testing of the down-selected design and material combination.