Development Of An Ultrasonic Sensing Technique To Measure Lubricant Viscosity In Engine Journal Bearing Insitu

This thesis presents a novel ultrasonic instrument for noninvasive and insitu characterization of journal bearing lubricant viscosity. In particular the application to journal bearings is described by noninvasively measuring the viscosity and localized power losses throughout operation. This ultrasonic viscometer is based on the reflection of polarized shear waves from a thin resonating coating layer to increase the measurement sensitivity in comparison to conventional ultrasonic methods.