  In this paper we study the effects of dynamic wetting on the immiscible
displacement of a high viscosity fluid subject to the radial injection of a
less viscous fluid in a Hele-Shaw cell. The displaced fluid can leave behind a
trailing film that coats the cell walls, dynamically affecting the pressure
drop at the fluid interface. By considering the non-linear pressure drop in a
boundary element formulation, we construct a Picard scheme to iteratively
predict the interfacial velocity and subsequent displacement in finite mobility
ratio flow regimes. Dynamic wetting delays the onset of finger bifurcation in
the late stages of interfacial growth, and at high local capillary numbers can
alter the fundamental mode of bifurcation, producing vastly different finger
morphologies. In low mobility ratio regimes, we see that finger interaction is
reduced and characteristic finger breaking mechanisms are delayed but never
fully inhibited. In high mobility ratio regimes, finger shielding is reduced
when dynamic wetting is present. Finger bifurcation is delayed which allows the
primary fingers to advance further into the domain before secondary fingers are
generated, reducing the level of competition.
