Conjugate Heat Transfer Calculations on GT Rotor Blade for Industrial Applications. Part I: Equivalent Internal Fluid Network Setup and Procedure Description

Gas turbine design has been characterized over the years by a continuous increase of the maximum cycle temperature, justi- fied by a corresponding increase of cycle efficiency and power output. In such way turbine components heat load management has become a compulsory activity and then, a reliable procedure to evaluate the blades and vanes metal temperatures, is, nowa- days, a crucial aspect for a safe components design. This two part work presents a three-dimensional conjugate heat transfer procedure developed in the framework of an internal research project of GE Oil & Gas. The procedure, applied to the first rotor blade of the MS5002E gas turbine, consists of a conjugate heat transfer anal- ysis in which the internal cooling system was modeled by an in-house one dimensional thermo-fluid network solver, the ex- ternal heat loads and pressure distribution have been evaluated through 3D CFD and the heat conduction in the solid is carried out through a 3D FEM solution. The first part of this work is focused on the description of the procedures in terms of set up of the equivalent fluid network model of internal cooling system and its tuning through experi- mental measurements of blade flow function. A first computa- tion of blade metal temperature was obtained by coupling with CFD computations carried out on a de-featured geometry of the blade. Achieved results are compared with the data of a metal- lographic analysis performed on a blade operated on an actual engine. Some discrepancies are observed between datasets, sug- gesting the necessity to improve the models, mainly from the CFD side.