Experimental Assessment of Drag and Rotordynamic Response for a Porous Type Gas Bearing

摘要

From estimated drag coefficients (a) Porous gas bearing operates with viscous drag. (b) Drag torque decreases as gas supply pressure increases. (c) Windage has significant effect at high speed, in particular at a high supply pressure. From rotordynamic response measurements (a) System natural frequency changes little as pressure supply increases. (b) Damping ratio decreases as gas pressurization into bearings increases. (c) Rotordynamic response is primarily synchronous. (d) Incipient subsynchronous whirl motions lock at the natural frequency and are benign, not a precursor to rotordynamic instability.