Calculations of the Stiffness of the Gas Film of the Dry Gas Seals of the Spiral Grooves Based on Computational Fluid Dynamics (CFD)

The three-dimensional model of the dry gas seal of a spiral groove was founded and its mesh was generated using Gambit software.Under the same specific working condition,a numerical simulation was carried out of the three-dimensional flow field of the micro space in the dry gas seal of the spiral groove with six different thicknesses of gas films using Fluent software,the pressure distribution and the radial pressure distribution of the flow field were obtained.The thrust of the gas films was obtained through the dynamic pressure generated through the gas films with different thicknesses,and the analysis expression of the thrust of the gas films about the thicknesses of the gas films was derived through the fit using least square method,and the stiffness of the gas films was obtained.The result shows that the stiffness of gas films was the function of negative index about the thicknesses of gas films.It was concluded that it was correct to use the function to solve the stiffness of the gas films through comparison of tests.