  We present in this Letter experimental results on the bidimensional flow
field around a cylinder penetrating into dense granular matter together with
drag force measurements. A hydrodynamic model based on extended kinetic theory
for dense granular flow reproduces well the flow localization close to the
cylinder and the corresponding scalings of the drag force, which is found to
not depend on velocity, but linearly on the pressure and on the cylinder
diameter and weakly on the grain size. Such a regime is found to be valid at a
low enough "granular" Reynolds number.
