IMPROVED ANALYTICAL CAPABILITIES FOR FOIL AIR BEARINGS

THIS PROPOSAL IS CONCERNING WITH THE DEVELOPMENT OF ANALYTICAL METHODS FOR COMPLIANT FOIL AIR BEARING PERFORMANCE PREDICTIONS, BEARING COEFFICIENTS CALCULATIONS AND ROTOR-BEARING SYSTEM ANALYSIS. THE ANALYSIS WILL TAKE INTO ACCOUNT THE THERMOHYDRODYNAMICS OF THE FLUID FILM AND THE THERMOELASTICITY OF THE COMBINED TOP AND BOTTOM FOILS. BOTH THRUST AND JOURNAL BEARING MODELS ASSIMILATING POPULAR FOIL BEARINGS WILL BE CONSIDERED. FOR THE FLUID FILM, A NAVIERSTOKES APPROACH IN CONJUNCTION WITH THE TWO EQUATION, K-E, TURBULENCE MODEL AND THE CONTROL VOLUME METHOD, WILL BE ADOPTED TO FORMULATE AND DISCRETIZE THE DIFFERENTIAL EQUATIONS. FOR THE FOILS, THE FORMULATION OF EQUATIONS WILL BE BASED ON A THIN PLATE MODEL WITH THE THERMAL EFFECT. COMPUTER CODES ARE TO BE DEVELOPED TO IMPLEMENT THE NUMERICAL SOLUTIONS FOR THE TWO REGIONS. BEARING PERFORMANCE CHARACTERISTICS SUCH AS LOAD CAPACITY, POWER LOSSES, FLOW RATES AND TEMPERATURE FIELDS WILL BE COMPUTED. THE BEARING COEFFICIENTS, STIFFNESS AND DAMPING, WILL BE COMPUTED. THE BEARING COEFFICIENTS WILL BE LINKED TO A ROTOR DYNAMICS CODE, RSVP (ROTOR-STRUCTUREVIBRATION-PROGRAM) FOR THE ROTOR-BEARING SYSTEM ANALYSIS.