INVESTIGATION ON CREEP CHARACTERISTIC OF NICKEL-BASE SINGLE CRYSTAL ALLOY DOUBLE WALL COOLING SPECIMEN

摘要

At present, advanced gas turbine are designed to work at increasingly higher turbine inlet temperatures (TIT) to obtain higher thermal efficiency and power. TIT of modern aircraft engine has exceeded temperature limit of high-temperature alloys application over 600C°. So turbine blade has to be cooled in order to work at an acceptable temperature environment. Double wall cooling technology with higher cooling efficiency which is developed by the RR and GE companies has become development trends of blade cooling. In this work, a flat double wall cooling structure is introduced. On basis of creep damage model considering interaction of cavitation and degradation, the creep behaviors of double wall cooling structure are investigated. Research shows that there are stress interferences among holes and pin fin. The higher stress region locates around holes. The lower stress region locates at pin fin. The distance of impingement hole and pin fin in the analysis model affect creep behavior seriously.