A comprehensive method of theoretical analysis for finite Squeeze Film Damper using finite element method is presented. The modified Reynolds equation in the film is solved using the finite element discretization. A Galerkin variational method is applied for solving modified Reynolds equation to determine the pressures as well as load carrying capacities. The pressure distribution and load carr...

Squeeze film dampers are widely used in aircraft engines, land-based gas turbines, and other rotating machines to improve system damping. They often have entrained air within the oil film, which is usually not taken into account in rotordynamics analysis due to lack of good formulations of the effects involved. The effects on the damping force calculation can be significant. This work presents ...

Damping in air gaps is studied at RF frequencies and modelled with a viscoelastic wave propagation model, since the traditional squeezed-film damping model is not valid in the MHz regime. The FEM study shows that above a certain frequency the wave propagation in the air gap can be modelled assuming closed damper borders. This closed-border problem is solved analytically from the linearized Navi...

Squeeze film dampers (SFDs) are components used in many industrial applications, ranging from turbochargers to jet engines. SFDs applied when the vibration levels or some instability threatens safe operation of machine. However, modeling these is difficult and somewhat counterintuitive due multiple complex phenomena involved. After a thorough investigation state art, most relevant for character...

A method is presented for the quick and accurate prediction of the stability of aerodynamically excited turbomachinery using real eigenvalue/eigenvector data obtained from a rotordynamics model. An expression is presented which uses the modal data and the transmitted torque to provide a numerical value of the relative stability of the system. This approach provides a powerful design tool to qui...

In order to reduce the mass, the new designs of turbojet engines use rotors working with higher speeds. These rotors are subjected to large unbalance during engine operational conditions. An additional damping might be necessary in order to enable working at rotation speeds higher than the critical ones. In order to achieve this objective, Integral S-shaped Squeeze Film Damper (ISSFD) and Multi...