Dynamic Coefficients for Compliant Foil Bearings

The cost effective application of compliant foil bearings (CFBS) to high-speed, high-temperature vehicle propulsion systems requires an improved understanding of the factors affecting their dynamic characteristics and accurate predictions of the coefficients to be used in rotordynamic analysis of these systems. Under this program, MiTi will establish the design and test methodology necessary to characterized the stiffness and damping of CFBs operating at high speeds, loads and temperatures. The test facility will have the capability to operate to speeds of over 100,000 rpm and temperatures to 150OF and will also accept bearings of different designs and diameters. Instrumentation with high temperature capability and high frequency response will be defined, as will the data acquisition and reduction methodology. Using an integrated hydrodynamic and compliant structural analysis tool MiTi will conduct a parametric study investigating the key parameters influencing CFB dynamic coefficients. Finally, a minimum of three different CFB configurations will be designed to allow investigation of key parameters and their impact on dynamic coefficients under Phase II testing. BENEFITS: The Developed test facility and methodology will be useful in developing CFB designs with improved dynamic performance. Improved designs will expand applications to turomachinery such as small gas turbines, turbochargers, compressors, expanders, alternators and the like.