CMC COMBUSTOR ON THE PATH TO 3100oF

The goal of the U.S. Army, Air Force, Navy, Marines, commercial aviation and industrial power plants to develop gas turbines capable of reliable operation at turbine inlet temperatures up to 3100oF. Consequently, there is a driving need to extend the capability of SiC CMCs and/or related Ceramic CMCs and associated thermalŚenvironmental barrier coatings (T-EBCs) to resist degradation in harsh moisture laded combustion and sand/dust ingestion (CMAS) conditions at much higher temperatures than GEÆs current state of the art 2400oF. In Phase 1, Technology Assessment and Transfer (TA&T) demonstrated that graded HfC-SiC matrix CMC samples densified by TA&TÆs rapid GP-RTG CVI process and coated with TA&TÆs Yb Hafnia multilayer T-EBC provided excellent protection capabilities in combined moisture-CMAS environments at 1550oC (2822oF). In Phase 2 Technology Assessment and Transfer (TA&T) proposes to optimize the CVI and/or CVI-PIP densification process and associated microstructures of the graded HfC-SiC CMCs. In parallel, TA&T will develop and optimize dual layer plasma spray Yttria Stabilized Zirconia-magnetron sputtered Yb Hafnia multilayer T-EBCs based on laboratory scale high humidity-CMAS testing. As a subcontractor Brayton Energy proposes a comprehensive approach to design, build and test an advanced, subscale CMC combustor for a medium lift helicopter engine. Brayton will in steps, use its proprietary software and CFD analysis to optimize a medium powered turboshaft helicopter combustor design and refined subscale CMC combustor test article design and complete their effort with a combustor instrumentation, test plan and analysis and comparison of combustor results from the High Particulate Ingestion Rig test with modeling predictions. TA&T will apply the optimized CMC densification and dual layer plasma spray YSZ-sputtered Yb Hafnia multilayer T-EBCs protocols to subscale combustor test article and send to ARL Aberdeen for test and evaluation. All the experimental details, results, analysis and recommendations for follow on scale up will be documented in a Final Report. An attractive near-term commercialization approach is also defined.