  The present works is focused on studying bifurcating solutions in
compressible fluid dynamics. On one side, the physics of the problem is
thoroughly investigated using high-fidelity simulations of the compressible
Navier-Stokes equations discretised with the Discontinuous Galerkin method. On
the other side, from a numerical modelling point of view, two different
non-intrusive reduced order modelling techniques are employed to predict the
overall behaviour of the bifurcation. Both approaches showed good agreement
with full-order simulations even in proximity of the bifurcating points where
the solution is particularly non-smooth.
