Students: Benstone Schwartz, Paul Gancitano
Fluid-film bearing applications continue to push the envelope on operating speed, specific load, and performance, requiring bearing technologies to keep pace. Modern applications commonly involve bearing operation in the transition and turbulent flow regions. Little data is available on the dynamic properties of bearings in this range. The Fluid Film Bearing Test Rig (FFBTR) aims to make these measurements possible.
Additionally, the FFBTR will provide additional validation of ROMAC codes including THPAD and MAXBRG. The development of an improved test rig with higher performance capability will lead to continued development and refinement of ROMAC bearing analysis tools for years to come.
Recently a comprehensive analysis of predicted uncertainty in measured dynamic coefficients was completed and the results indicated that the original design of the test rig needed to be modified. To minimize the final measurement uncertainty new technologies such as the “Active Load Cell” concept are being evaluated.
An “Active Load Cell” test bed is being developed in parallel with the FFBTR to validate the concept and ensure the best accuracy possible for bearing force measurements. This piece of equipment will utilize electrodynamic shakers and a control algorithm to accurately identify fluid-film bearing forces. The determination of these forces are critical to understanding the stiffness and damping coefficients of a fluid-film bearing, particularly at high frequencies.
All possible design changes are simulated in a high-fidelity Simulink model in an attempt to fully understand the dynamics of the system and make sure significant factors are not overlooked. In spring 2016 a great deal of progress made in the development of the high-fidelity simulation. Some preliminary results were presented in the summer at the annual meeting. The high-fidelity simulations are currently being finalized.