The turbine blade or bucket poses some additional challenges compared to other hot gas path components because it rotates! And with that, comes windage effects and losses and concerns of the effect of the unsteadiness between the rotor/stator. This section highlights research on internal cooling of turbine blades as well as impingement cooling which is also an important method for internal cooling of nozzles and combustion liners.
Effect of Coolant Injection Angle on Nozzle Endwall Film Cooling in Linear Cascade
Internal cooling of the gas turbine blade/vanes with the help of two-pass channels is one of the effective methods to reduce the metal temperatures. The price paid for high heat transfer is pressure drop. There is also tradeoffs between the number of cavities and configuration. These series of papers look at optimizing various aspects of cooling passages including the trailing edge region.
Comparison of Steady and Unsteady RANS Heat Transfer
Simulations of Hub and Endwall of a Turbine Blade Passage
It takes 500 clock hours to reach a converged steady state solution for the uncooled turbine blade passage model. It takes the same
model 25,000 clock hours to converge the unsteady simulation.
The question is: Is the added time and complexity of running
unsteady worth it?
Heat Transfer Distribution on Smooth and Roughened Surfaces Under an Array of Angled Impinging Jets
Impingement is a common means of convectively cooling surfaces in numerous industrial applications. One such application is the cooling of gas turbine hot gas path components such as the combustion liner, transition piece, and turbine buckets and nozzles. A two- or three-dimensional array of jets can be used for convectively cooling turbine parts. The air jets impinge at the surface to be cooled and are directed along a channel formed by the cool surface and the jet plate. In such arrangements, the downstream jets are subjected to a crossflow from the upstream jets.