No abstract

The effect of misalignment on the performance of a completeAn isothermal perfect gas is used as the lubricant fluid. Results are shell gas foil bearing is discussed. An iterative theoretical model presented demonstrating the effect of misalignment on load capacity, based on the finite element method is used. The model includes minimum clearance, and moments acting normal to the journal. membrane and elastic foundation effects in the structural model. KEY WORDS Final manuscript approved September 15, 1992 Foil Bearing, Journal a = vector of nodal degrees of freedom A = domain of lubricant film and foil c = nominal bearing clearance C I = boundary of lubricant film with pressure condition CP = boundary of foil with displacement condition d_ = nominal diameter of bearing D = stiffness matrix e = eccentricity E = modulus of elasticity f x 3 f r = journal loads in X and Y directions I; = load vector in structural analysis F = distributed force on elastic foundation h = lubricant film clearance L = length of bearing i = linear operator K = stiffness of elastic foundation K = structural stiffness matrix KBC = boundary condition contribution to stiffness matrix m = boundary mass flux Mx,M, = journal moments about X and Y axes N = array of basis functions P -= lubricant film pressure P = boundary pressure PA = ambient pressure P = distributed loading vector in structural model r = nominal bearing radius ri,foil,ri,rhfi = nominal radii of foil and shaft nodes R = gas constant s = curvilinear coordinate along boundary of foil and lubricant film t = thickness of foil T = gas film temperature = foil deflection vector = foil boundary conditions = radial foil deflection at node i = axial, radial, and circumferential displacements in global coordinate system = displacement in the plane of element in circumferential direction = displacement in direction perpendicular to plane of element = surface velocity of journal = displacement in the plane of element in axial direction W = normalized load = -pAr2 = axial coordinate PA = bearing compliance = -cK = angular orientation of elements = relaxation factor = eccentricity ratio = C = circumferential coordinate = eccentricity angle of journal = rotations about radial, axial, and circumferential axes in global coordinate system = constraint multiplier 6 p o r 2 = bearing number = -PA c2 = viscosity = Poison's ratio = initial foil stresses = attitude angle = skew angles about X and Y axes = angular speed of journal Downloaded by ["Queen's University Libraries, Kingston"] at 07:36 03 January 2015 830