Modern day advanced gas turbines are operated at exceedingly high temperatures; by running at such high temperatures, engines can achieve greater power output and thermal efficiency. However, the current firing temperature for combustion exceeds the turbine blade material limit [1]. As this firing temperature increases, heat transfer into turbine components increases as well. Therefore, it is necessary to introduce a cooling mechanism to these blades in order to protect the material as the engine is run at these elevated temperatures. Because turbine blades have a complex geometry, several cooling schemes have been introduced to cool the various parts of each blade. A detailed overview of several cooling methods can be found in open literature for external as well as internal turbine blade cooling.

Among the different cooling techniques, impingement cooling produces some of the highest heat transfer coefficients. This is due to highly localized cooling near the stagnation region of the impinging jets. However, the tradeoff of having higher heat transfer is that this method also produces higher thermal stresses. As such, this method is typically only used in locations where thermal loads are very high. Some examples of this include: turbine guide vanes, rotor blades, rotor disks, and combustor liners [2].