Download or read book Unsteady Analysis of the Fluid Film Forces in a Long Bearing Squeeze Film Damper written by Paul Schallhorn and published by . This book was released on 1998 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Unsteady Long Bearing Squeeze Film Damper Model Part 1 written by P. A. Schallhorn and published by BiblioGov. This book was released on 2013-08 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper, the first of a two-part series, presents results of an unsteady rotordynamic analysis of a long-bearing squeeze film damper executing circular centered orbits using a fluid circuit approach. A series of nodes and branches represent the geometry of the flow circuit. The mass and momentum conservation equations are solved to predict the pressure distribution in the squeeze film. The motion of the bearing is simulated by the variation of geometry within the flow path. The modeling methodology is benchmarked against published experimental long-bearing squeeze film damper test results. The model provides good agreement with the experimental damping coefficient.

Download or read book An Unsteady Long Bearing Squeeze Film Damper Model Part 2 written by P. A. Schallhorn and published by BiblioGov. This book was released on 2013-08 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper, the second of a two-part series, presents results of an unsteady rotordynamic analysis of a long-bearing squeeze film damper executing orbits about an off center position using a fluid circuit approach. A series of nodes and branches represent the geometry of the flow circuit. The mass and momentum conservation equations are solved to predict the pressure distribution in the squeeze film. The motion of the bearing is simulated by the variation of geometry within the flow path. This effort represents the first modeling approach which allows for an arbitrary orbit size about an arbitrary position.

Download or read book Nonlinear analysis of squeeze film dampers design and application for aircraft engines written by Edgar J. Gunter and published by . This book was released on 1976 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady state and Transient Analysis of a Squeeze Film Damper Bearing for Rotor Stability written by Lloyd Edward Barrett and published by . This book was released on 1975 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Unsteady Long bearing Squeeze Film Damper Model written by Paul A. Schallhorn and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Analysis of Squeeze Film Damper Systems written by Xuehai Li and published by . This book was released on 1985 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Rapid Technique for Calculating the Fluid film Forces in a Short Squeeze film Damper Bearing with Limited Maxium Positive Pressure and Subatmospheric Cavitation Pressure written by R. A. Cookson and published by . This book was released on 1979 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design and application of squeeze film dampers for turbomachinery stabilization written by Edgar J. Gunter and published by . This book was released on 1975 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamentals of Fluid Film Lubrication written by Bernard J. Hamrock and published by CRC Press. This book was released on 2004-03-15 with total page 794 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specifically focusing on fluid film, hydrodynamic, and elastohydrodynamic lubrication, this edition studies the most important principles of fluid film lubrication for the correct design of bearings, gears, and rolling operations, and for the prevention of friction and wear in engineering designs. It explains various theories, procedures, and equations for improved solutions to machining challenges. Providing more than 1120 display equations and an introductory section in each chapter, Fundamentals of Fluid Film Lubrication, Second Edition facilitates the analysis of any machine element that uses fluid film lubrication and strengthens understanding of critical design concepts.

Download or read book Nonlinear Dynamics of the Squeeze Film Damper written by Bindingnavale Ranga Krishna Kumar and published by . This book was released on 1980 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Hydrodynamic Force Coefficients for a Grooved Squeeze Film Damper written by Jia Xin Zhang and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rotordynamics of Turbomachinery written by John M. Vance and published by John Wiley & Sons. This book was released on 1991-01-16 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the rotordynamic considerations that are important to the successful design or troubleshooting of a turbomachine. Shows how bearing design, fluid seals, and rotor geometry affect rotordynamic behavior (vibration, shaft whirling, bearing loads, and critical speeds), and describes two successful computational methods for rotordynamic analysis in terms that can be understood by practicing engineers. Gives descriptive accounts of the state of the art in several areas of the field and presents important mathematical or computational concepts, describing equations and formulas in physical terms for better understanding. Also offers tips for troubleshooting unstable machines and provides practical interpretations of vibration measurements.

Download or read book Performance of a Short Open End Squeeze Film Damper With Feed Holes written by Gary Daniel Bradley and published by . This book was released on 2013 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing rotor flexibility and shaft speeds, turbomachinery undergoes large dynamic loads and displacements. Squeeze film dampers (SFDs) are a type of fluid film bearing used in rotating machinery to attenuate rotor vibration, provide mechanical isolation, and/or to tune the placement of system critical speeds. Industry has a keen interest in designing SFDs that are small, lightweight, and mechanically simple. To achieve this, one must have a full understanding of how various design features affect the SFD forced performance. This thesis presents a comprehensive analysis, experimental and theoretical, of a short (L=25.4 mm) open ends SFD design incorporating three lubricant feed holes (without a circumferential feed groove). The damper radial clearance (c=127 [mu]m), L/D ratio (0.2), and lubricant (ISO VG2) have similar dimensions and properties as in actual SFDs for aircraft engine applications. The work presents the identification of experimental force coefficients (K, C, M) from a 2-DOF system model for circular and elliptical orbit tests over the frequency range [omega]=10-250Hz. The whirl amplitudes range from r=0.05c-0.6c, while the static eccentricity ranges from eS=0-0.5c. Analysis of the measured film land pressures evidence that the deep end grooves (provisions for installation of end seals) contribute to the generation of dynamic pressures in an almost purely inertial fashion. Film land dynamic pressures show both viscous and inertial effects. Experimental pressure traces show the occurrence of significant air ingestion for orbits with amplitudes r>0.4c, and lubricant vapor cavitation when pressures drop to the lubricant saturation pressure (PSAT~0 bar). Identified force coefficients show the damper configuration offers direct damping coefficients that are more sensitive to increases in static eccentricity (eS) than to increases in amplitude of whirl (r). On the other hand, SFD inertia coefficients are more sensitive to increases in the amplitude of whirl than to increases in static eccentricity. For small amplitude motions, the added or virtual mass of the damper is as large as 27% of the bearing cartridge mass (MBC=15.15 kg). The identified force coefficients are shown to be insensitive to the orbit type (circular or elliptical) and the number of open feed holes (3, 2, or 1). Comparisons of damping coefficients between a damper employing a circumferential feed groove1 and the current damper employing feed holes (no groove), show that both dampers offer similar damping coefficients, irrespective of the orbit amplitude or static eccentricity. On the other hand, the grooved damper shows much larger inertia force coefficients, at least ~60% more. Predictions from a physics based model agree well with the experimental damping coefficients, however for large orbit motion, over predict inertia coefficients due to the model neglecting convective inertia effects. Credence is given to the validity of the linearized force coefficients by comparing the actual dissipated energy to the estimated dissipated energy derived from the identified force coefficients. The percent difference is below 25% for all test conditions, and in fact is shown to be less than 5% for certain combinations of orbit amplitude (r), static eccentricity (eS), and whirl frequency ([omega]). The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151179

Download or read book The Effect of Fluid Inertia on Squeeze film Damper Force Response written by Luis Alberto San Andres Alvares and published by . This book was released on 1985 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Fluid Inertia and Cavitation on the Force Coefficients of a Squeeze Film Damper written by Si Young Jung and published by . This book was released on 1990 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Squeeze Film Damper Technology written by J. Walton and published by . This book was released on 1986 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: A test rig was constructed and proper instrumentation provided for measuring the performance of squeeze film dampers. The tests provided both conceptual understanding of the mechanism of damper operation by providing data on the viscous and inertia components of the fluid film, and on the modalities of oil delivery via the feeding holes and grooves, for both sealed and unsealed dampers. Quantitative data were then provided for the entire gamut of variables attending the design of squeeze film dampers and these were then compared with theoretical predictions. A particularly important part of the test was the visual documentation via both still and motion pictures of cavitation which is still not a fully understood phenomenon under dynamic conditions. Failure tests were conducted to simulate damper response to extreme loadings such as resulting form loss of a turbine blade. While the correlation with theory was shown to be generally valid up to the upper ranges of speeds, the quality of correlation was much affected by the encountered variation of boundary conditions in the feed grooves. The latter thus emerges as an aspect of squeeze film damper mechanics which needs further study.