ABSTRACT

The present study analyzes the effects of L/D ratio and bearing radial clearance of 3-lobe taper land bearing on stability of flexible rotor system. The pressure distribution in a fluid film journal bearing was calculated using incompressible Reynolds equation, implemented via finite difference method (FDM). Stiffness and damping coefficients were calculated with respect to Sommerfeld number. As an example of flexible rotor system a high speed steam turbine is used. The rotor was modeled with 1d finite elements based on Euler-Bernoulli beam theory. Stability of the flexible rotor system was estimated using logarithmic decrement. Six cases were analyzed and recommendations for optimal bearing configuration were proposed.