A gas turbine generally includes a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section progressively increases the pressure of a working fluid entering the gas turbine and supplies this compressed working fluid to the combustion section. The compressed working fluid and a fuel (e.g., natural gas) mix within the combustion section and burn in a combustion chamber to generate high pressure and high temperature combustion gases. The combustion gases flow from the combustion section into the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a shaft connected, e.g., to a generator to produce electricity. The combustion gases then exit the gas turbine via the exhaust section.
The turbine section includes a plurality of turbine rotor blades, which extract kinetic energy from the combustion gases flowing therethrough. These rotor blades generally operate in extremely high temperature environments. In order to achieve adequate service life, the rotor blades typically include an internal cooling cavity or envelope. The internal cooling cavity may include a plurality of cooling passages arranged in a serpentine-like manner. During operation of the gas turbine, a cooling medium such as compressed air is routed through the internal cooling cavity and/or cooling passages to cool the rotor blade.
The thickness of the rotor blade walls (i.e., the distance between the outer surface of the rotor blade and the inner surface of the rotor blade defining internal cooling cavity) is crucial for heat transfer, flow distribution, and mechanical load transfer. Accordingly, a rotor blade having a wall thickness distribution to better facilitate heat transfer, flow distribution, and mechanical load transfer would be useful in the art.