Dynamic Stability of Rotating Shafts in Viscous Fluids

Stability characteristics of an overhanging shaft immersed in a viscous fluid are investigated experimentally. The predominance of two effects, damping and virtual mass, are separated and explored as they affect amplitude and critical speed. A correlation equation for amplitude as a function of viscosity, velocity, and mass is developed with the aid of statistical regression analysis. The techniques of regression analysis are summarized in the Appendix.