In this manuscript, both experimental and numerical investigations have been carried out to study the mechanism of separation energy and flow phenomena in the counter flow vortex tube. This manuscript presents a complete comparison between the experimental investigation and CFD analysis. The experimental model was manufactured with (total length of 104 mm and the inner diameter of 8 mm, and made of cast iron) tested under different inlet pressures (4, 5 and 6 bar). The thermal performance has been studied for hot and cold outlet temperature as a function of mass fraction α (0.3-0.8). Three-dimensional numerical modeling using the k-ε model used with code (Fluent 6.3.26). Two types of velocity components are studied (axial and swirl). The results show any increase in both cold mass fraction and inlet pressure caused to increase ΔTc, and the maximum ΔTc value occurs at P = 6 bar. The coefficient of performance (COP) of two important factors in the vortex tube which are a heat pump and a refrigerator have been evaluated, which ranged from 0.25 to 0.74. A different axial location (Z/L = 0.2, 0.5, and 0.8) was modeled to evaluate swirl velocity and radial profiles, where the swirl velocity has the highest value. The maximum axial velocity is 93, where it occurs at the tube axis close to the inlet exit (Z/L=0.2). The results showed a good agreement for experimental and numerical analysis.