Fluid Dynamics of Film Cooling Investigated by Large-Eddy Simulation
|Research Area||Large-eddy simulation of complex engineering flows, film cooling|
|Principal Investigator(s)||Prof. L. Kleiser|
The high temperature of turbine blades imposes a limit on the turbine performance. Film cooling is used to lower the blade temperature by ejecting cold gas through holes close to the leading edge into the boundary layer. This flow configuration is very complex, in terms of geometry as well as in terms of physical phenomena involved.
Numerical simulations of film cooling configurations are mostly limited to Reynolds averaged Navier-Stokes (RANS) simulations which are by design not capable of capturing the full physics of this configuration. Therefore, we investigate this flow with large-eddy simulations (LES) which are capable of resolving the larger flow structures in time. For modelling the subgrid scales we use our own approximate deconvolution model (ADM).
We aim at simulating very large film cooling configurations with an accurately represented geometry. Although, LES has only about one percent of the computational cost of direct numerical simulations (DNS), such simulations still require exceptional computing resources.