Thermo-Structural Analysis of First Stage Gas Turbine Rotor Blade Materials for Optimum Service Performance

摘要

During gasturbine operation, the vibration that occurs at high speed, hot gases enteringthe combustion chamber and other operational factors affect the longevity ofgas turbine blade. This paper is focused on theselection of suitable materials that can withstand the severe working conditionand thermo-structuralanalysis using Finite Element method (FEM) to determine the behaviour of each material under servicecondition. Cambridge Engineering Software (CES) was employed in the materialselection process where GTD111, U500 and IN 738 were identified prior toanalyzing U500 and IN 738 due to desired mechanical properties over GTD111.Employing ANSYS R15.0 in the steadystate thermal analysis, maximum service temperature of 736.49oCand maximum Total heatflux of 4.345x105 W/m2 was obtained for IN 738 material while maximum servicetemperature of 728.29oC and maximum Total heat flux of 4.1746x105 W/m2was obtained for U500 bladematerial. For structural static analysis, maximum von-mises stress of 454 MPaand total deformation of 0.16221 obtained for IN 738 while maximum von-misesstress of 416 MPa and total deformation of 0.12125 was obtained for U500 blade material. While the FEAanalytical results for both materials exhibited less variations between eachother, IN 738 displayed better thermal characteristics, whereas, U500 presentedsatisfactory structural static results and above all, von-mises stressesobtained for both materials was below their yield strength and meltingtemperature. Hence, gas turbine blade materials should be assessed thoroughlyfor structural and thermal conditions before manufacturing.