Large-Eddy Simulation of Double-Row Compound-Angle Film-Cooling: Computational Aspects

Film-cooling is an important technique allowing to increase the thermal efficiency of gas turbines. By blowing cool air through an array of small holes in the turbine blades a thin fluid film is set up shielding the blades from the hot gas arriving from the combustion chamber.

This work presents computational aspects of a Large-Eddy Simulation of a particular film-cooling configuration known to provide a high level of effectiveness. The simulation employs the block-structured finite-volume Navier-Stokes code NSMB for compressible flows including the Approximate Deconvolution Model for subgrid turbulence modeling, the Synthetic-Eddy Method for turbulent inflow generation and reflection-reducing outflow boundary conditions. The performance of principal routines is analyzed first for a sequential simulation of a canonical flat plate turbulent boundary layer, showing a high efficiency above 35% of the most time-consuming routines on a NEC SX-8. A strong scaling test of the film-cooling setup shows reasonable parallel speedup up to 32 processors of an SX-8. For both cases, with the new architecture SX-9 a lower relative performance is achieved compared to the SX-8.