Large eddy simulation applications

The objective of the present lecture is to provide an overview of what can be achieved today using state-of-the-art Large Eddy Simulations for turbomachinery components, emphasizing the gain in accuracy and the cost of the method. First, a review of the published literature is performed, highlighting notable achievements in terms of turbomachinery applications with LES. In the second part, two applications of LES in turbomachinery are presented. The first application is a high-pressure turbine stator, the VKI Turmunsflat case, experimentally studied by Sieverding et al. [128]. Simulations with the RANS, URANS and LES methods are compared, clearly illustrating the fundamental differences between the three approaches. The computational cost of the methods is assessed, and compared against the benefits in terms of physical accuracy. The second test case is a highly-loaded high-pressure turbine blade cascade studied within a Conjugate Heat Transfer (CHT) framework. This multi-physics case illustrates the coupling between a LES flow solver and a solid heat-transfer code. Comparisons are made to assess the relative gains obtained with the LES approach (as compared to a RANS simulation) and due to the coupling with the heat-transfer code (as compared to adiabatic simulations)