Modeling of Heat Transfer in Exhaust Nozzle of Gas Turbines

Abstract

Thermal barrier coatings (TBCs) are applied blades, vanes, combustion chamber walls and exhaust nozzles in gas turbines in order to protect the metallic parts and to increase performance at high temperatures. In this present work, numerical steady-state exhaust nozzle heat transfer mechanisms were studied. Radiation to the external surface of coating and conduction to the coating and superalloy nozzle were modeled. The effective heat transfer coefficient was simulated. This analysis includes the CFD model of gas, coating and metal parts.

Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings

“…As the gas turbine blade/vane materials must possess high temperature strength, toughness, and corrosion resistance, nickel-based superalloys have been the materials of choice for these components. 14 Considerable re-search effort has been devoted toward reducing the thermal conductivity of EB-PVD grown YSZ coatings, [15][16][17] and coatings with high porosity bearing a columnar structure have been shown to yield superior thermal barrier properties. However, further improvement in the metallurgy of these alloys appears unlikely to keep pace with the demand for increasing gas inlet temperature in the quest for higher efficiency.…”