Bearing Dynamic Coefficients in Rotordynamics

Łukasz Breńkacz is an Assistant Professor and Research Associate at the Institute of Fluid Flow Machinery, Polish Academy of Sciences in Gdańsk, Poland. His research foci are on machinery design, the analysis of bearing systems, computer simulations, and experimental diagnostics of rotating machinery.

• List of Figures xList of Tables xviPreface xviiSymbols and Abbreviations xixAbout the Companion Website xxi1 Introduction 11.1 Current State of Knowledge 11.2 Review of the Literature on Numerical Determination of Dynamic Coefficients of Bearings 61.3 Review of the Literature on Experimental Determination of Dynamic Coefficients of Bearings 71.4 Purpose and Scope of the Work 102 Practical Applications of Bearing Dynamic Coefficients 142.1 Single Degree of Freedom System Oscillations 162.1.1 Constant excitation Force 182.1.2 Excitation by Unbalance 202.1.3 Impact of Damping and Stiffness 242.2 Oscillation of Mass with Two Degrees of Freedom 262.3 Cross-Coupled Stiffness and Damping Coefficients 282.4 Summary 333 Characteristics of the Research Subject 343.1 Basic Technical Data of the Laboratory Test Rig 343.2 Analysis of Rotor Dynamics 363.3 Analysis of the Supporting Structure 423.4 Summary 444 Research Tools 464.1 Test Equipment 464.2 Test.Lab Software 494.3 Samcef Rotors Software 514.4 Matlab Software 514.5 MESWIR Series Software (KINWIR, LDW, NLDW) 524.6 Abaqus Software 535 Algorithms for the Experimental Determination of Dynamic Coefficients of Bearings 555.1 Development of the Calculation Algorithm 555.2 Verification of the Calculation Algorithm on the Basis of a Numerical Model 585.3 Results of Calculations of Dynamic Coefficients of Bearings 625.4 Summary 646 Inclusion of the Impact of an Unbalanced Rotor 656.1 Calculation Scheme 656.2 Definition of the Scope of Identification 676.3 Results of the Calculation of Dynamic Coefficients of Bearings Including Rotor Unbalance 686.4 Summary 697 Sensitivity Analysis of the Experimental Method of Determining Dynamic Coefficients of Bearings 707.1 Method of Carrying Out a Sensitivity Analysis 707.2 Description of the Reference Model 717.3 Influence of the Stiffness of the Rotor Material 717.4 Influence of Uneven Force Distribution on Two Bearings 727.5 Changing the Direction of the Excitation Force and its Effect on the Results Obtained 757.6 Eddy Current Sensor Displacement Impact Assessment 767.7 Calculation Results for an Asymmetrical Rotor 777.8 Summary 798 Experimental Studies 818.1 Software Used for Processing of Signals from Experimental Research 828.2 Software Used for Calculations of Dynamic Coefficients of Bearings 838.3 Preparation of Experimental Tests 858.4 Implementation of Experimental Research 878.5 Processing of the Signal Measured During Experimental Tests 918.6 Results of Calculations of Dynamic Coefficients of Hydrodynamic Bearings on the Basis of Experimental Research 938.7 Verification of Results Obtained 988.8 Summary 1009 Numerical Calculations of Bearing Dynamic Coefficients 1029.1 Method of Calculating Dynamic Coefficients of Bearings 1029.2 Calculation of Dynamic Coefficients of Bearings Using a Method with Linear Calculation Algorithm 1079.3 Calculation of Dynamic Coefficients of Bearings Using a Method with Non-linear Calculation Algorithm 1139.4 Verification of Results Obtained 1199.5 Summary 12310 Comparison of Bearing Dynamic Coefficients Calculated with Different Methods 12511 Summary and Conclusions 129Appendix A 134Appendix B 145Appendix C 152Research Funding 155References 156Index 163