A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section.
In the pursuit of ever high efficiencies, gas turbine engine manufacturers have long relied on high turbine inlet temperatures to provide boosts to overall engine performance. In typical modern gas turbine engine applications, the gas path temperatures within the turbine section exceed the melting point of the component constituted materials. In order to operate the gas turbine engine at these temperatures, dedicated cooling air is extracted from the compressor section and used to cool the gas path components in the turbine section. The use of compressed air from the compressor section for cooling purposes decreases the efficiency of the gas turbine engine because the compressor section must produce more compressed air than is necessary for combustion. Therefore, minimizing the use of cooling air in the turbine section is of particular importance.
The coriolis effect negatively impacts suction side heat transfer performance on rotating airfoils, such as turbine blades. The coriolis effect forces the air off the suction side of the airfoil causing a secondary flow rotation that scrubs the pressure side of the airfoil and leaves very large and separated boundary layers on the suction side. These separated boundary layers have poor heat transfer capability due to low near-wall thermal gradient. This effect is exacerbated in flows that are radially inward in nature. Under the coriolis effect, the suction side loss of heat transfer of the rotating airfoil is typically accompanied by a boost in pressure side heat transfer. Therefore, there is a need to augment the effectiveness of suction-side rotating airfoil cooling