Fig. 8

Vibration behavior and rotor trajectory at \(\varepsilon_{o} = 0.6\,,\,\,\varepsilon^{\prime}(0) = 0.05\) using modified Krierger-Dougherty viscosity model with \(\Phi = 0.005\,\,and\,\,\beta = 7.77\): (a & b) stable oscillations (\(\lambda = 36\)); (c & d) critical case (\(\lambda_{cr} = 44.125)\) and (e & f) unstable oscillations (\(\lambda = 56)\).