Ansys Employee

There isn't a 2013 version, unless you mean the version that was available in 2013? The current release is 2023R2.

Porous zone values are probably DEFINE_PROFILE (I've not checked), DEFINE_PROPERTIES tends to be for density, viscosity and the like. Assuming you've got an axi-symmetric model your results look reasonable. What does the pressure field look like? 

Does the paper list any of the porous media coefficients? Or give any pressure against flow data to let you work it out?