I was reading a paper "Experimental modeling of a curved Ranque–Hilsch vortex tube refrigerator" and trying to validate the vortex tubes using ANSYS FLUENT. All the data points are close to the experimental results except cold mass fraction greater than 0.7. The problem I am facing is that the hot exit temperature becomes elevated instead of decreasing at 0.7 cold mass fraction at 3 bar inlet pressure. Why it is decreasing? I read other papers especially the vortex tube paper by Skye et al, their hot exit temperature is increasing at the higher cold mass fraction. Reference: https://doi.org/10.1016/j.ijrefrig.2011.02.013