Design of a Biomorphic Groove Dry Gas Seal Based on Bird Wing Outlines

In order to solve the problems of a dry gas seal (DGS), such as the opening force or the axial gas film stiffness between two faces is insufficient and face wear or instability occurs sometimes, the concept of bionic design for a DGS is introduced in this paper. After the effects of various flying wings of typical birds on their flying ability were analyzed and the geometric feature parameters of the wing outlines were presented, a biomorphic groove has been invented based on the classic type of a DGS with spiral grooves onto its one of two sealing faces (S-DGS) and by use of the geometric reconstruction technique. Then a new type of a biomorphic groove dry gas seal (B-DGS) was presented. The geometric model of such a B-DGS was presented. The Reynolds equation for controlling gas film pressure between two sealing faces of a B-DGS or a S-DGS was solved by use of the finite difference method. The variations of sealing performance with the major geometric parameters of a biomorphic groove were simulated. The comparisons of sealing performance parameters, such as the opening force, gas film stiffness, between a B-DGS and a S-DGS were made under the same operating conditions. The results show that the sealing performance of a B-DGS will be improved to some extend compared to that of a S-DGS when the geometric parameters of biomorphic grooves are set reasonably, then the face lift-off ability during start-up or shut-down and the stability of such a B-DGS will be promoted. The bionic design of a DGS is of practical significance.