Development of an ultrasonic sensing technique to measure lubricant viscosity in engine journal bearing in-situ

• Main Author: Schirru, Michele (Author)
• Format: Electronic eBook
• Language: English
• Published: Cham, Switzerland : Springer, 2017.
• Series: Springer theses.
• Subjects: Lubricating oils > Viscosity.; Ultrasonic testing.; elektronické knihy; electronic books
• ISBN: 9783319534084; 9783319534077
• Physical Description: 1 online resource

This thesis presents a novel ultrasonic instrument for non-invasive and in-situ characterization of journal bearing lubricant viscosity. In particular, the application to journal bearings is described by non-invasively measuring the viscosity and localized power losses throughout operation. This ult...

Table of Contents:

• Supervisor's Foreword; Contents; Nomenclature; Introduction; Thesis Layout; Summary; 1 Introduction; 1.1 Statement of the Problem; 1.2 Project Aims; 1.3 Thesis Layout; References; 2 Background on Viscosity and Lubrication; 2.1 Definition of Viscosity; 2.1.1 Viscosity Relation with Temperature; 2.1.2 Viscosity Index; 2.1.3 Viscosity and Pressure; 2.1.4 Viscosity and Shear Rate; 2.2 Viscosity Measurement; 2.2.1 Capillary Viscometers; 2.2.2 Rotational Viscometers; 2.2.3 Falling Body Viscometers; 2.2.4 Vibrational Viscometers; 2.2.5 High Pressure Viscometers; 2.2.6 High Shear Viscometers.
• 2.3 Engine Lubricating Oil Composition2.3.1 Base Oils; 2.3.2 Viscosity Modifiers; 2.3.3 Detergents; 2.4 Oil Classification by Viscosity; 2.5 Lubrication Principles in Mechanical Components; 2.5.1 The Stribeck Curve; 2.5.2 Journal Bearing Lubrication; 2.5.3 Considerations for Journal Bearing Design; 2.6 Conclusions; References; 3 Background on Ultrasound; 3.1 Introduction to Ultrasound; 3.2 Ultrasound and Material Properties; 3.3 Ultrasonic Transducers; 3.3.1 The Piezoelectric Effect; 3.3.2 Ultrasonic Transducer Type; 3.3.3 Other Type of Ultrasonic Transducers.
• 3.4 Characteristics of Ultrasonic Signals3.5 Transducers Arrangements; 3.6 Reflection of Ultrasound Waves at Interface; 3.6.1 Reflection and Transmission in a Three-Layered System; 3.6.2 Reflection of Shear Waves at Solid-Liquid Boundary; 3.7 Conclusions; References; 4 Literature Review; 4.1 The Crystal Resonator; 4.2 The Resonating Plate/Rod; 4.3 Reflectance Methodologies; 4.3.1 The Newtonian Reflection Model; 4.3.2 The Greenwood Model; 4.4 The Attenuation Method; 4.4.1 Ultrasonic Spectroscopy Methods; 4.5 Ultrasonic Resonator to Analyse Lubricating Oils.
• 4.6 Comparison of Ultrasonic Viscometers and Conventional Viscometers4.7 Conclusions; References; 5 A Novel Ultrasonic Model for Non-Newtonian Fluids; 5.1 Introduction; 5.2 The Maxwell Fluid Model; 5.3 The Ultrasonic Model for Non-Newtonian Fluids; 5.4 Comparison of Models; 5.5 Non-Newtonian Ultrasonic Model Sensitivity Analysis; 5.5.1 Reflection Coefficient; 5.5.2 Fluid Density; 5.5.3 Solid Density; 5.6 Conclusions; References; 6 Viscosity Measurements at an Aluminium-Oil Boundary; 6.1 Ultrasonic Apparatus; 6.1.1 The Transducers; 6.1.2 The Cables; 6.1.3 Thermocouple Calibration.
• 6.1.4 Test Lubricants6.1.5 Experimental Protocol; 6.2 Signal Processing; 6.3 Conventional Reflectance Technique: Results; 6.4 Conventional Reflectance Technique: Acoustic Mismatch; 6.5 Conclusions; References; 7 The Matching Layer Method; 7.1 Origins of the Matching Layer Methodology; 7.2 Matching Layer Theory; 7.3 Measurement Apparatus; 7.3.1 Instrumentation; 7.3.2 Test Cell and Matching Layer; 7.3.3 Samples Tested; 7.4 Signal Processing and Data Analysis; 7.5 Results; 7.5.1 Measurement Sensitivity Increment; 7.5.2 Viscosity Results for Newtonian Oils.