Effect of different inlet pressures of vortex tube on internal flow field

Abstract

Numerical simulations were used to investigate the distribution of the internal pressure, velocity, and temperature fields in the vortex tube (VOTU) at inlet pressures of 1-4 MPa to reveal the causes of temperature separation. A three-dimensional model with a nozzle flow channel number of 5 was drawn, and the simulation was performed in Fluent 19.0 with CO2 as the working fluid. The simulation results show that when the inlet pressure of the VOTU is greater than 2 MPa, the temperature separation between the hot and cold air streams of the VOTU gradually increases with the increase of the inlet pressure. The maximum temperature is 285 K and the minimum temperature is 257 K at an inlet pressure of 1.0 MPa, and the maximum temperature is 319 K and the minimum temperature is 243 K at an inlet pressure of 4.0 MPa. As the inlet pressure increases, the temperature difference inside the VOTU will also increase. In the high-pressure condition, the wall thickness and sealing degree of the VOTU design should be increased accordingly, while the inner wall side of the VOTU needs to use wear-resistant materials to delay the long-term scouring of the VOTU caused by high-speed airflow. The results of the study have certain guiding significance for the design and manufacture of VOTUs.