Download or read book Cavitation Effects on the Performance of Squeeze Film Damper Bearings written by Fouad Youssef Zeidan and published by . This book was released on 1989 with total page 658 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 Cavitation Effects on Squeeze Film Damper Performance written by N. S. Feng and published by . This book was released on 1988 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Modeling and Performance of Squeeze Film Damper Bearings written by John A. Tichy and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The squeeze film damper is a bearing used in high speed turbomachinery to reduce rotor dynamics problem. A pure squeezing action in a thin film of lubricating fluid provides the desired damping. Due to the unsteady nature of the problem, a key assumption inherent in Reynolds' theory is not force, that of neglecting the inertia of the fluid. In addition, the fluid pressure often seeks a level lower than the vapor pressure, in which case a vapor cavity forms. Numerical calculations and supporting experiments are performed for a damper operating in the regime in which fluid inertia effects are important. A large error in the classical theory is seen at modified Reynolds number up to 30. These are the highest Reynolds numbers, heretofore reported, approaching those of actual practice. Regarding cavitation, a simplified model is developed. Compared to results obtained using the finite element method, considerable numerical work is saved and little accuracy is lost. Agreement with experimental measurements of cavity size and pressure is excellent. Preliminary studies have been undertaken concerning the use of electroheological fluids in squeeze film dampers.
Download or read book Squeeze Film Damper Technology written by J. Walowit and published by . This book was released on 1986 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present report this report provides refinements and extensions to the analytical treatment of squeeze film dampers reported in Part I. Specifically, it incorporates the effects of squeeze film dampers cavitation on performance based on short-bearing theory and particularly on the damping properties. The analysis also provides means of a more accurate evaluation of the flow resistance in the feeding holes by taking account of the stagnation pressures at the entrance to the clearance space. With these modifications introduced into the computer program, a parametric study is then conducted on the effects of the many variables on the operation of sealed and unsealed dampers, both hole- and groove-fed. Among the variables considered are clearance, size, eccentricity ratio, supply pressure and system frequency. Conclusions are drawn as to the optimum values of these parameters with regard to best damper performance. Keywords: Rotordynamics, Cavitation Fluid Inertia.
Download or read book Advances in Active Bearings in Rotating Machinery written by Athanasios Chasalevris and published by Springer Nature. This book was released on 2023-06-26 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on cutting-edge experimental and numerical findings related to the application of active bearings, including smart ones, in rotating machinery. It discusses their role in improving stability and control of rotor systems and reports in depth on the corresponding modeling and control approaches. Chapters are based on peer-reviewed contributions to the 1st Workshop on Active Bearings in Rotating Machinery (ABROM 2022), held on June 29- 30, 2022, in Athens, Greece, and organized in collaboration between the School of Mechanical Engineering of The National Technical University of Athens (NTUA) and the Faculty of Mechanical Engineering of Karlsruhe Institute of Technology (KIT). In connection with the increasing digital transformation of machine elements, this book offers a timely perspective and extensive information on testing methods and experimental procedures involved in the development of intelligent rotors for industrial applications.
Download or read book Squeeze Film Damper Technology written by J. Walton and published by . This book was released on 1986 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present report this report provides refinements and extensions to the analytical treatment of squeeze film dampers reported in Part I. Specifically, it incorporates the effects of squeeze film dampers cavitation on performance based on short-bearing theory and particularly on the damping properties. The analysis also provides means of a more accurate evaluation of the flow resistance in the feeding holes by taking account of the stagnation pressures at the entrance to the clearance space. With these modifications introduced into the computer program, a parametric study is then conducted on the effects of the many variables on the operation of sealed and unsealed dampers, both hole- and groove-fed. Among the variables considered are clearance, size, eccentricity ratio, supply pressure and system frequency. Conclusions are drawn as to the optimum values of these parameters with regard to best damper performance.
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 568 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 The Shock and Vibration Digest written by and published by . This book was released on 1986 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Cavitation in Squeeze Film Journal Bearings written by Amir Bashirzadeh Tabrizi and published by . This book was released on 2008 with total page 256 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 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 Effect of Fluid Inertia in Squeeze Film Damper Bearings a Heuristic and Physical Description written by J. A. TICHY and published by . This book was released on 1983 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamics of Pumps written by Christopher E. Brennen and published by Cambridge University Press. This book was released on 2011-03-28 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrodynamics of Pumps is a reference for pump experts and a textbook for advanced students. It examines the fluid dynamics of liquid turbomachines, particularly pumps, focusing on special problems and design issues associated with the flow of liquid through a rotating machine. There are two characteristics of a liquid that lead to problems and cause a significantly different set of concerns than those in gas turbines. These are the potential for cavitation and the high density of liquids, which enhances the possibility of damaging, unsteady flows and forces. The book begins with an introduction to the subject, including cavitation, unsteady flows and turbomachinery, basic pump design and performance principles. Chapter topics include flow features, cavitation parameters and inception, bubble dynamics, cavitation effects on pump performance, and unsteady flows and vibration in pumps - discussed in the three final chapters. The book is richly illustrated and includes many practical examples.
Download or read book ASME Technical Papers written by and published by . This book was released on 1999 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
