  Viscoelasticity weakens the asymmetry of laminar shedding flow behind a blunt
body in a free domain. In the present study, this finding is confirmed by four
unsteady viscoelastic flows with asymmetric flow configuration, i.e., flow over
an inclined flat plate with various angles of incidence, flow over a rotating
circular cylinder, flow over a circular cylinder with asymmetric slip boundary
distribution, and flow over an inclined row of eight equally closely spaced
circular cylinders (which can be considered as a single large blunt body)
through direct numerical simulation combined with the Peterlin approximation of
the finitely extensible nonlinear elastic (FENE-P) model. At high Weissenberg
number, an arc shape region with high elastic stress, which is similar to shock
wave, forms in the frontal area of the blunt body. This region acts as a
stationary shield to separate the flow into different regions. Thus, the free
stream resembles to pass this shield instead of the original blunt body. As
this shield has symmetric feature, the wake flow restores symmetry.
