In order to describe the movement of rotor system in an aero-engine that combines the rotation and procession together

the Reynolds equation of gas film seal damper (GFSD) was deducted.The fluid-solid coupling relationship among rotor

gas film and metal rubber ring was constructed based on the movement equation and displacement coordinated relationship

so the solution process of steady-state pressure field was clear and the design method for the stiffness of metal rubber was put forward.The finite difference method was employed to solve the steady-state pressure field

and the effects of working parameters and structural parameters on the steady-state properties were analyzed

which could provide references for the structural design of GFSD

and finally the mass flow-rate between GFSD and straight labyrinth seal was compared.The results show that the appropriate stiffness of metal rubber can make GFSD adjust the clearance of gas film adaptively.In order to maintain a dynamic lubrication condition

the larger the ratio of length and diameter

and the smaller the stiffness of metal rubber and clearance of gas film is

the better the steady-state properties are.The mass flow-ratio of GFSD is much less than that of straight labyrinth seal

and therefore GFSD could meet the requirements of the seals in advanced aero-engines.