Numerical Study on Heat Transfer Characteristics of Gas Turbine Coated Blades

A one dimensional computational model was presented for heat transfer in a typical gas turbine coated blade composed of a ceramic layer, a metallic adhesion layer and a metallic wall in a high temperature combustion gas flow environment. Thermal radiation transfer in the nongray anisotropic scattering ceramic layer and transient coupled heat transfer in a coated blade were solved by DOM and FVM respectively with the consideration of combustion gas radiation. Heat transfer characteristics with various influencing factors for a specific gas turbine coated blade were numerically studied. Results show that the blade thermally responds much fast in a transient process with a time constant of several seconds. Steady state temperature drop in the ceramic layer increases with combustion gas temperature almost linearly. Both the heat transfer coefficient of cooling fluid in the blade interior and the ceramic layer thickness can enlarge the temperature drop in the ceramic layer significantly while scattering mode in the ceramic layer has little influence on the temperature level in metallic wall.