  We revisit recently published high-fidelity implicit large eddy simulation
datasets obtained with a high-order discontinuous Galerkin spectral element
method and analyse them using Proper Orthogonal Decomposition (POD) as well as
Spectral Proper Orthogonal Decomposition (SPOD). The first configuration is the
MTU T161 low-pressure turbine cascade with resolved end wall boundary layers in
a clean version and one with incoming turbulent wakes. We focus on the
behaviour of the laminar separation bubble and the secondary flow system and
how these phenomena are affected by incoming wakes. The second configuration is
a transonic compressor cascade in which we analyse the unsteady behaviour of
the shock wave boundary layer interaction. Throughout the paper, we try to
discuss not only the flow physics but also insights into how the modal
decomposition techniques can help facilitate understanding and where their
limitations are.
