  The domain wall dynamics driven by an out of plane magnetic field was
measured for a series of magnetic trilayers with different strengths of the
interfacial Dzyaloshinskii-Moriya interaction (DMI). The features of the
field-driven domain wall velocity curves strongly depend on the amplitude of
the HD field stabilising chiral N\'eel walls. The measured Walker velocity,
which in systems with large DMI is maintained after the Walker field giving
rise to a velocity plateau up to the Slonczewski field HS, can be easily
related to the DMI strength. Yet, when the DMI field HD and the domain wall
demagnetising field HDW have comparable values, a careful analysis needs to be
done in order to evaluate the impact of the DMI on the domain wall velocity. By
means of a one-dimensional model and 2D simulations, we successfully extend
this method to explain experimental results to cases where HD and HDW are
comparable.
