Session: 40-03 Compressor Secondary Flows and Interactions

Paper Number: 124264

124264 - The Unsteady Shock-Boundary Layer Interaction in a Compressor Cascade – Part 2: High-Fidelity Simulation 

Jet engine compressors at transonic operating conditions are typically subject to strong unsteadiness caused by the oscillation of the shock structure. The transient behaviour of the shock-boundary layer interaction (SBLI) results in unreliable performance of the engine and cannot be properly captured by traditional Reynolds-averaged Navier-Stokes (RANS) codes used in the design process, hence leading to overly conservative design margins and compromised performance. Accurate modelling of SBLI can therefore lead to a better understanding of the mechanisms driving the unsteadiness and support the design of more efficient compressor blade design.

To combat the draw-backs of low-fidelity RANS, time- and space-resolved simulations such as large-eddy simulations (LES) have seen a rise in popularity in the turbomachinery community over the last decade. But while an increase in available computational resources has led to the publication of turbine LES at realistic operating conditions recently, simulations of shock-buffeting phenomena on compressor blades have remained scarce. This is, at least in part, due to the challenging nature of these flows as they require shock capturing methods, long run times to capture the typically low-frequency buffeting and high spatial resolution.

In the second part of this three-paper series, we report results of implicit LES of the Transonic Cascade TeamAero, a transonic compressor cascade designed at the German Aerospace Center (DLR). A high-order accurate discontinuous Galerkin spectral element method with a finite-volume subcell shock capturing approach tailored for the split-form DG method previously described in [1] is used for the numerical discretization. Low-frequency large-amplitude oscillations of the shock wave are resolved through long simulation times where time-resolved data is used to extract distinct features of the shock-wave boundary layer interaction through temporal and spatial correlations.

REFERENCES

[1]     B.F. Klose, C. Morsbach, M. Bergmann, A. Hergt, J. Klinner, S. Grund, E. Kügeler, A Numerical Test Rig for Turbomachinery Flows Based on Large Eddy Simulations With a High-Order Discontinuous Galerkin Scheme - Part 2: Shock-Capturing and Transonic Flows. Journal of Turbomachinery, 2023, doi:10.1115/1.4063827.

Presenting Author: Bjoern F. Klose German Aerospace Center (DLR)

Presenting Author Biography: Bjoern F. Klose (PhD) is a post-doctoral research assistant at the Institute of Test and Simulation for Gas Turbines at DLR, where his area of research includes the development of numerical methods for the high-order Discontinuous Galerkin scheme in the turbomachinery flow solver “TRACE” and the conduction of high-resolution transonic turbomachinery simulations. He received his doctoral degree from the University of California San Diego in 2021 for the work on low-Reynolds number airfoil flow and analysis of flow instabilities in the context of Lagrangian structures.

Authors:

Bjoern F. Klose German Aerospace Center (DLR)
Christian Morsbach German Aerospace Center (DLR)
Michael Bergmann German Aerospace Center (DLR)
Edwin Joseph Munoz Lopez German Aerospace Center (DLR)
Alexander Hergt German Aerospace Center (DLR)
Edmund Kügeler German Aerospace Center (DLR)