Vortex Tube CFD Simulation,ANSYS Fluent Training

Description

Vortex Tube CFD Simulation, ANSYS Fluent Training

description

A mechanical-thermal vortex tube splits a compressed air flow (or any inert gas) into hot and cold streams. Standard components of a vortex tube include an inlet nozzle(s), a hot end tube, a vortex chamber, a cold orifice, and a control valve(s) or plug(s) at the hot end. Both left and right-side exits are possible.

In this project, a vortex tube is simulated using ANSYS Fluent software. The air enters the domain with a static pressure of 7 bars and a total temperature equal to 300K. After that, it starts to rotate inside the tube in a high-speed vortex motion.

The rotating gas creates hot and cold streams within the vortex tube. The separation of the hot and cold streams occurs due to the difference in angular momentum between the gas particles.

Finally, the hot airflow enters the outlet chamber, while the cold airflow returns and passes through the left side.

The geometry of the solution is created using SpaceClaim,the polyhedra-type mesh is generated via Fluent Meshing software. After all, the whole number of elements is 497,635.

Vortex Tube CFD Simulation Methodology

The Density-Based solver is chosen to model the airflow. The air density is selected as the ideal gas, and its viscosity is Sutherland.

The Spalart Almaras model is used to model the turbulence of the fluid.

Conclusion

After the solution, we obtained the temperature, pressure, and velocity contour inside the vortex tube. The flow vectors show the air’s rotational movement and how the air with the lower momentum returns to the cold outlet.

Also, the static pressure, the temperature of the air, and the change in its density are apparent in contours.

In conclusion, the temperature of the left and right outlets, which are named as cold and hot outlets, are lower and higher than the inlet temperature, respectively.

The following table shows the temperature of the airflow at different boundaries.

  Mass-Weighted Average of Total Temperature                           [K]

                          ——————————–                                         ——————–

                               cold_outlet                                                          287.24653

                               hot_outlet                                                           353.01502

                             inlet                                                                     300