Experimental Rotordynamic Force Coefficients for a Diffusion Bonded Compliant Hybrid Journal Gas Bearing Utilizing Fluid-Filled Hermetic Dampers

摘要

This work focused on the experimental results of a CHGB with HSFDs in the bearing support aimed to replace an oil-lubricatedintegral squeeze film damper bearing used in a 10MW sCO_2 tur-bomachinery application. Static results showed stable bearing pad temperatures at 27 krpm operating speed, and low leakage values that are speed and load independent. Dynamic results showed stiffness and damping coefficients that are relatively speed and load independent, with low, same-sign, cross-coupled terms. Direct stiffness and damping showed frequency dependency with higher stiffness and lower damping values at high frequencies. The bearing structure provides high damping via HSFDs, yet the full potential of utilizing the damping is hindered by increasing structure stiffness with increasing frequency. The ongoing research strives to address the frequency dependent nature of the HSFDs to eventually provide a CHGB that exploits the potential of the new HSFD technology.