  We consider a liquid drop placed on a smooth homogeneous solid substrate as
it spreads from rest to its eventual equilibrium state. The problem is studied
numerically in the framework of a model where the contact angle formed by the
drop's free surface with the substrate is not prescribed as a function of the
contact-line speed and has to be found as part of the solution. It is shown
that in this spontaneous spreading, as the drop starts moving and the contact
line accelerates, the dynamic contact angle decreases with the contact-line
speed, which is in line with what experimental observations on spontaneous
wetting report, though it is contrary to what is assumed in most models aimed
at describing experiments on the "forced" spreading. Nontrivial aspects of the
implementation of the model in a finite-element-based algorithm are discussed
in detail.
