Numerical Investigation of the VKI Turbine Blade by Large Eddy Simulation

5 Conclusions

In the frame of this work, the numerical investigations of the flow through the VKI turbine cascade were performed by means of Large Eddy Simulation.

The numerical simulation has delivered detailed aerodynamical information as well as showed problems and the importance of a proper mesh generation for LES. The mesh down to the wall and along the wall must be fine enough in order to resolve the expected structures.

The importance of upstream turbulence was underestimated. Therefore, no suitable inlet boundary condition was applied to the simulations. The lack of the upstream fluctuations caused deficiency of the turbulence development in the boundary layer and therefore bypass transition was impossible. In the simulations the transitions proceeded in the natural way, hence the transitions were quieter and the development of the turbulent boundary farther downstream was slower.

At the present times computational resources necessary to perform a (U)RANS simulation of the considered case does not cause a problem. Computations of flows through complex geometries at higher Reynolds numbers with LES are still the challenge for CFD and super computers.