The model is a squeeze film damper supporting a shaft in circular precession motion. The stiffness and damping characteristics are calculated at the adimensional equilibrium position XX = 0.5. The precession rotational velocity is 500 rad/s.
The bearing properties are as follows:
| Clearance: 2.54 x 10-5 m |
| Length: 0.005 m |
| Radius: 0.025 m |
| Viscosity: 0.07 Pa·s |
A perturbation increment of 5 x 10-4 is used.
/title, Squeeze Film Damper - Circular synchronous precession ! ** Bearing parameters mass = 1 ! unused xclear = 2.54e-5 length = 0.005 radius = 0.025 epsinc = 5e-4 mu = 0.07 ! ** Equilibrium position XX = 0.5 omegaprec = 500 ! precession u1 = XX*xclear /prep7 ! ** Nodes n, 1, 0 n, 2, 0 n, 3, 0 ! ** Elements et, 1, 21,,, 2 ! 3D no rotary inertias r, 1, mass type,1 real,1 e, 2 et, 2, 214 keyopt,2,1, 2 ! Reynolds integration r, 2, xclear, length, radius, ,, epsinc rmore,, omegaprec ! ** Material mp,visc,2,mu ! ** Mesh type,2 real,2 mat,2 e, 1, 2, 3 ! ** Boundary conditions d, all, all, 0.0 ddel, 2, UX ddel, 2, UY finish ! ** Static Analysis with specified displacement /solu antype, static d,2,ux,u1 outres,all,all solve finish /post1 set,last esel,,elem,,2 etable, fx, smisc,1 etable, fy, smisc,2 etable, theta1, nmisc,1 etable, theta2, nmisc,2 etable, mofp, nmisc,3 etable, thetap, nmisc,4 etable, hmin, nmisc,5 etable, thetah, nmisc,6 pretab etable, kxx, nmisc,7 etable, kyy, nmisc,8 etable, kxy, nmisc,9 etable, kyx, nmisc,10 pretab, kxx, kyy, kxy, kyx etable, cxx, nmisc,11 etable, cyy, nmisc,12 etable, cxy, nmisc,13 etable, cyx, nmisc,14 pretab, cxx, cyy, cxy, cyx finish
