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 Analysis of Nonlinear Systems with Application to Squeeze Film Dampers written by Mohammed Ali Rezvani and published by . This book was released on 1994 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Experimentation of Squeeze Film Dampers Considering Fluid Inertia Film Cavitation and Design Features in Aircraft Engine written by Tieshu Fan and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unbalance-induced vibration in aircraft engines is the major source of cabin noise and discomfort for passengers. One key component in attenuating the vibration level in an engine rotor is the squeeze film damper (SFD). The implementation of SFDs in high-speed turbomachinery increases the rotor stability and reduces the vibration amplitude at critical speeds. Despite the successful operation of SFDs in aero engines for decades, currently applied SFD models are not sophisticated enough to recognize unique features that affect damping performance. Development of an accurate and computationally efficient model has been an ongoing challenge. The object of this thesis is to develop SFD models that incorporate the fluid inertia, film cavitation, lubricant seals, and supply mechanism to provide a precise prediction of damper behavior at high operating speeds. To be specific, the fluid inertia is resolved by the momentum approximation method and perturbation method; film cavitation is formulated by the Elrod cavitation algorithm [1] and the linear complementarity problem method [2]; the effect of lubricant seals is addressed by the leakage flow at the seal groove for piston ring seals [3]; the supply mechanism is modeled by the flow interaction at the central groove. Moreover, the developed models are integrated into a rotordynamic system to estimate the critical speeds and vibration amplitudes. To accelerate the simulation time, a polynomial interpolation technique for SFD models is introduced to solve for the SFD forces under different operating conditions. Both the steady-state response and the frequency response are presented for an open SFD application. To validate the developed SFD models, an experiment for a single flexible rotor supported with two identical SFDs is executed. Displacements of both the central disk and support SFDs are measured to correlate the theoretical prediction. Some design and operation parameters including the film clearance and supply pressure are examined in the test to evaluate their effect. Results have shown excellent agreement in terms of the critical speed and vibration amplitude. In addition, several other design parameters such as the film length and bearing stiffness are discussed in the model sensitivity to demonstrate the significance of their impact.
Download or read book Nonlinear Analysis of Squeeze Film Damper Systems written by Xuehai Li and published by . This book was released on 1989 with total page 100 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 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 Experimental Study of Uncentralized Squeeze Film Dampers written by Roger D. Quinn and published by . This book was released on 1983 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of an Aero engine Squeeze film Damper written by Muzaffer Doğan and published by . This book was released on 1983 with total page 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 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the previous three parts of this series, procedures are outlined for the interaction of damper analysis with rotordynamic requirements in order to arrive at an operationally viable system incorporating squeeze film dampers. The design considerations include the various practical aspects of rotating machinery such as spacing, damper location, spring supports, the proximity of various critical, manufacturing tolerances, etc. The procedures are then applied to the fan of a TF-41 engine, resulting in a new design which promises substantially better performance than the one presently used. (Author).
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 Experimental Analysis of Damper Behavior of Squeeze Film Dampers for Gas Turbine Engines bearings written by S. C. Kaushal and published by . This book was released on 1984 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engine Dynamic Analysis with General Nonlinear Finite Element Codes written by and published by . This book was released on 1991 with total page 96 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.
Download or read book Oil Squeeze Film Dampers for Reducing Vibration of Aircraft Gas Turbine Engines written by Toshio Miyachi and published by . This book was released on 1979 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of High Load Dampers written by and published by . This book was released on 1981 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of non circular squeeze film damper bearing performance written by Du Fay Kik and published by . This book was released on 2003 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Squeeze Film Damper written by Andre Slonopas and published by . This book was released on 2011 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
