The talk focuses on a stationary problem in a rarefied gas confined between two coaxial cylinders. The boundary values introduced generate a helicoidal motion of the fluid together with an heat transfer. The physical problem is described using the equations of Rational Extended Thermodynamics. The results are compared with the prediction of the corresponding Classical Thermodynamics model and significative differences are observed. The role of the helicoidal motion is also analyzed through a comparison with the cases of only rotation or only axial flows.