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 The Shock and Vibration Digest written by and published by . This book was released on 1983 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Proceedings of the 10th International Conference on Rotor Dynamics IFToMM written by Katia Lucchesi Cavalca and published by Springer. This book was released on 2018-08-20 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: IFToMM conferences have a history of success due to the various advances achieved in the field of rotor dynamics over the past three decades. These meetings have since become a leading global event, bringing together specialists from industry and academia to promote the exchange of knowledge, ideas, and information on the latest developments in the dynamics of rotating machinery. The scope of the conference is broad, including e.g. active components and vibration control, balancing, bearings, condition monitoring, dynamic analysis and stability, wind turbines and generators, electromechanical interactions in rotor dynamics and turbochargers. The proceedings are divided into four volumes. This first volume covers the following main topics: Active Components and Vibration Control; Balancing; Bearings: Fluid Film Bearings, Magnetic Bearings, Rolling Bearings and Seals; and Blades, Bladed Systems and Impellers.
Download or read book The Shock and Vibration Digest written by and published by . This book was released on 2002 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotordynamic Instability Problems in High performance Turbomachinery 1986 written by and published by . This book was released on 1986 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of Force Coefficients in Two Squeeze Film Dampers with a Central Groove written by Sanjeev Seshagiri and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Squeeze Film Dampers (SFD) provide viscous damping in rotor bearing systems to reduce lateral vibration amplitudes and to isolate mechanical components. Aircraft engine shafts, often supported on roller bearings, operate at high rotational speeds and are susceptible to large amplitude shaft whirl due to rotor imbalance. SFDs aid to reduce such large whirl amplitudes while also eliminating rotor instabilities. The current work quantifies experimentally the forced performance of two parallel squeeze SFDs separated by a central groove. Force coefficients are identified in a specialized SFD test rig constructed to undergo similar operating and loading conditions as in jet engines. Of interest is to quantify the effect of a central feed groove on the forced performance of SFDs and to validate predictions from a computational tool. The test rig comprises of an elastically supported bearing structure and one of two journals. Tests are conducted on two open ends SFDs, both with diameter D and nominal radial clearance c; each damper with two parallel film land lengths L= 1/5 D and 2L, separated by a feed groove of width L and depth 3/4 L. ISO VG 2 grade lubricant oil flows into the central groove via 3 orifices, 120 degrees apart, and then through the film lands to finally exit to ambient. In operation, a static loader pulls the bearing to various static off center positions with respect to the stationary journal, and electromagnetic shakers (2,200 N) excite the test system with single frequency loads over a frequency range to generate rectilinear, circular and elliptical orbits with specified motion amplitudes. A frequency domain method identifies the SFD mechanical parameters, viz., stiffness, damping, and added mass coefficients. The long damper generates 7 times more direct damping and 2 times more added mass compared to the short length damper. The damping coefficients are sensitive to the static eccentricity (up to 50 percent c) while showing lesser dependency on the amplitude of whirl motion (up to 20 percent c). On the other hand, added mass coefficients are nearly constant with static eccentricity and decrease with higher amplitudes of motion. The magnitudes of identified cross-coupled coefficients are insignificant for all imposed operating conditions for either damper. Large dynamic pressures recorded in the central groove demonstrate the groove does not isolate the film lands by merely acting as a source of lubricant, but contributes to the generation of large added mass coefficients. The recorded dynamic pressures in the film lands and central groove do not evidence lubricant vapor or gas cavitation for the tested static eccentricities and amplitudes of motion. The direct damping coefficients for both dampers are independent of excitation frequency over the frequency range of the tests. Predictions derived from a novel SFD computational tool that includes flow interactions in the central groove and oil supply orifices agree well with the experimental force coefficients for both dampers. The current work advances the state of the art in SFDs for jet engines.
Download or read book Paper written by and published by . This book was released on 1999 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Engineering for Power written by and published by . This book was released on 1983 with total page 976 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 ASME Technical Papers written by and published by . This book was released on 1999 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotordynamic Instability Problems in High performance Turbomachinery 1990 written by and published by . This book was released on 1991 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA SP written by and published by . This book was released on 1992 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Defence Science Journal written by and published by . This book was released on 1988 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1982 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
