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 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 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 Tribology and Dynamics of Engine and Powertrain written by Homer Rahnejat and published by Elsevier. This book was released on 2010-09-30 with total page 1059 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tribology, the science of friction, wear and lubrication, is one of the cornerstones of engineering’s quest for efficiency and conservation of resources. Tribology and dynamics of engine and powertrain: fundamentals, applications and future trends provides an authoritative and comprehensive overview of the disciplines of dynamics and tribology using a multi-physics and multi-scale approach to improve automotive engine and powertrain technology.Part one reviews the fundamental aspects of the physics of motion, particularly the multi-body approach to multi-physics, multi-scale problem solving in tribology. Fundamental issues in tribology are then described in detail,from surface phenomena in thin-film tribology, to impact dynamics, fluid film and elastohydrodynamic lubrication means of measurement and evaluation. These chapters provide an understanding of the theoretical foundation for Part II which includes many aspects of the physics of motion at a multitude of interaction scales from large displacement dynamics to noise and vibration tribology, all of which affect engines and powertrains. Many chapters are contributed by well-established practitioners disseminating their valuable knowledge and expertise on specific engine and powertrain sub-systems. These include overviews of engine and powertrain issues, engine bearings, piston systems, valve trains, transmission and many aspects of drivetrain systems. The final part of the book considers the emerging areas of microengines and gears as well as nano-scale surface engineering.With its distinguished editor and international team of academic and industry contributors, Tribology and dynamics of engine and powertrain is a standard work for automotive engineers and all those researching NVH and tribological issues in engineering. Reviews fundamental aspects of physics in motion, specifically the multi-body approach to multi physics Describes essential issues in tribology from surface phenomena in thin film tribology to impact dynamics Examines specific engine and powertrain sub-systems including engine bearings, piston systems and value trains
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 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 Nonlinear Structural Analysis written by and published by . This book was released on 1984 with total page 180 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 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 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 Engine Structures written by and published by . This book was released on 1988 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paper written by and published by . This book was released on 2000 with total page 478 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 1986 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the 2nd International Conference on Mechanical System Dynamics written by Xiaoting Rui and published by Springer Nature. This book was released on with total page 4383 pages. Available in PDF, EPUB and Kindle. Book excerpt:
