  Mixed-dimensional mathematical models for flow in fractured media have been
prevalent in the modeling community for almost two decades, utilizing the
explicit representation of fractures by lower-dimensional manifolds embedded in
the surrounding porous media. In this work, for the first time, direct
qualitative and quantitative comparisons of mixed-dimensional models are drawn
against laboratory experiments. Dedicated displacement experiments of
steady-state laminar flow in fractured media are investigated using both
high-resolution PET images as well as state-of-the-art numerical simulations.
