Influence of the Groove Width on the Aerostatic Dry Gas Seal

Aerostatic dry gas seal has attracted more and more attention because of its advantages with low friction loss, low heat generation, large opening force and high gas film stiffness at low-speed operation situation. The influence of the radial groove width ratio, B-w, on the performance of the aerostatic dry gas seal has been investigated by an analytical method by solving the N-S equation in order to understand the performance of the seal further more. The results show that the effect of the radial groove width ratio, B-w, on the opening force and on the gas film stiffness is obvious. The opening force decreases with the radial groove width ratio, B-w, increasing at the same gas film thickness. The situation of the gas film stiffness is complex. When the gas film thickness is smaller than a critical value, about 6 mu m as to the example presented in this paper, the gas film stiffness increases with the B-w, increasing, but the gas film stiffness decreases with the B-w, increasing when thickness is larger than the critical value. With the increasing of B-w, the leakage to the atmosphere, Q2, increases, but the leakage to the process fluid, Q1, reduces.