Oil Film Dynamics In Aero Engine Bearing Chambers
DOWNLOAD
Download Oil Film Dynamics In Aero Engine Bearing Chambers PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Oil Film Dynamics In Aero Engine Bearing Chambers book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Oil Film Dynamics In Aero Engine Bearing Chambers
DOWNLOAD
Author : Amir Aleem Hashmi
language : en
Publisher: Logos Verlag Berlin GmbH
Release Date : 2012
Oil Film Dynamics In Aero Engine Bearing Chambers written by Amir Aleem Hashmi and has been published by Logos Verlag Berlin GmbH this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with Science categories.
Aero engine bearing chambers are complex machine elements inside the engines, supporting up to three concentric shafts on bearings. For safety reasons, the aero engines always employ rolling-element type bearings and therefore require a sufficient oil supply for lubrication in order to guarantee a reliable operation. As a consequence, a complex two-phase flow consisting of oil and sealing air governs the bearing chambers. A highly dynamic oil film, flowing along the chamber walls, plays a vital role to fulfill the tasks of cooling, lubricating and cleaning the bearing chambers. The design and optimization process of the bearing chambers requires a detailed understanding in order to accurately simulate the film behaviour inside the bearing chambers. Based on the earlier experimental investigations, it is known that near the scavenge off-take a relatively thick film exists. The numerical model to simulate these films must therefore take into account the elliptical behaviour of such films. Among the different models, the Volume Of Fluid (VOF) Model offers the best compromise between accuracy and efforts. However, preliminary attempts to model a fully developed and turbulent test case from literature revealed an unphysical pressure drop and velocity profile in the gas phase above the film flow. An inadequate turbulence modelling near the gas-liquid interface was identified as the problem source. The 2-Equation turbulence models (k- epsilon & k- omega) were extended to achieve a substantial improvement.
Oil Droplet Impact Dynamics In Aero Engine Bearing Chambers Correlations Derived From Direct Numerical Simulations
DOWNLOAD
Author : Davide Peduto
language : en
Publisher: Logos Verlag Berlin GmbH
Release Date : 2015-06-30
Oil Droplet Impact Dynamics In Aero Engine Bearing Chambers Correlations Derived From Direct Numerical Simulations written by Davide Peduto and has been published by Logos Verlag Berlin GmbH this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-06-30 with Science categories.
Bearing Chambers in Aero-Engines are located near the rolling-element type of bearings which support the shafts and accomodate the resulting thrust loads. One of the main task of the bearing chambers is, beside an efficient scavenging of the lubricating oil, the cooling of the hot compartments. A very complex two-phase air-oil flow takes usually place in these bearing chambers consisting of oil droplet-laden air flows and shear-driven liquid wall films. The interaction of the droplets with the wall films is significantly influencing the wall heat transfer and the cooling performance of these systems. For this reason, a detailed characterization and modelling of the mass and momentum exchange between droplets and wall films for the unique impingement parameter range in bearing chambers is inevitable. This scientific report investigates the oil droplet impact dynamics for typical impingement regimes relevant to aero-engine bearing chambers. The application of a Direct Numerical Simulation (DNS) technique based on the Volume-of-Fluid (VOF) method and coupled with a gradient-based adaptive mesh refinement (AMR) technique allowed to characterize the drop impact dynamics during various single micro- and millimeter drop impacts onto thin and thick films. With the help of a special numerical treatment, a self-perturbing mechanism is installed that leads to the correct resolution of the crown disintegration process. The numerical methodology was thoroughly validated using the experimental results of millimeter sized drop impacts onto deep liquid pools. These results were developed with an enhanced back-illuminated high-speed imaging and Particle Tracking Velocimetry (PTV) technique. New insights into the cavity penetration, the crown's breakup dynamics and the secondary droplet characteristics following a single drop impact have been developed with the help of the isolated variation of different parameters of influence. Particularly the influence of the Froude number, the impingement angle, and the cavity-wall interaction delivered results to date not reported in scientific literature. Beside the advances in fundamental physics describing the drop impact dynamics with the help of the numerical and experimental results, a set of correlations could also be derived. From these correlations, a drop-film interaction model was formulated that is suitable for the parameter range found in bearing chambers.
Oil Film Dynamics In Aero Engine Bearing Chambers
DOWNLOAD
Author : Amir A. Hashmi
language : en
Publisher:
Release Date : 2012
Oil Film Dynamics In Aero Engine Bearing Chambers written by Amir A. Hashmi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012 with Electronic book categories.
Annotation Aero engine bearing chambers are complex machine elements inside the engines, supporting up to three concentric shafts on bearings. For safety reasons, the aero engines always employ rolling-element type bearings and therefore require a sufficient oil supply for lubrication in order to guarantee a reliable operation. As a consequence, a complex two-phase flow consisting of oil and sealing air governs the bearing chambers. A highly dynamic oil film, flowing along the chamber walls, plays a vital role to fulfill the tasks of cooling, lubricating and cleaning the bearing chambers. The design and optimization process of the bearing chambers requires a detailed understanding in order to accurately simulate the film behaviour inside the bearing chambers. Based on the earlier experimental investigations, it is known that near the scavenge off-take a relatively thick film exists. The numerical model to simulate these films must therefore take into account the elliptical behaviour of such films. Among the different models, the Volume Of Fluid (VOF) Model offers the best compromise between accuracy and efforts. However, preliminary attempts to model a fully developed and turbulent test case from literature revealed an unphysical pressure drop and velocity profile in the gas phase above the film flow. An inadequate turbulence modelling near the gas-liquid interface was identified as the problem source. The 2-Equation turbulence models (k- epsilon & k- omega) were extended to achieve a substantial improvement.
Analysis Of The Oil Film On The Inside Surface Of An Aero Engine Bearing Chamber Housing
DOWNLOAD
Author : John W. Chew
language : en
Publisher:
Release Date : 1996
Analysis Of The Oil Film On The Inside Surface Of An Aero Engine Bearing Chamber Housing written by John W. Chew and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1996 with categories.
Presented at the International Gas Turbine and Aeroengine Congress & Exhibition Birmingham, UK - June 10-13, 1996.
Uncertainty Quantification In Computational Fluid Dynamics And Aircraft Engines
DOWNLOAD
Author : Francesco Montomoli
language : en
Publisher: Springer
Release Date : 2018-06-21
Uncertainty Quantification In Computational Fluid Dynamics And Aircraft Engines written by Francesco Montomoli and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-06-21 with Technology & Engineering categories.
This book introduces design techniques developed to increase the safety of aircraft engines, and demonstrates how the application of stochastic methods can overcome problems in the accurate prediction of engine lift caused by manufacturing error. This in turn addresses the issue of achieving required safety margins when hampered by limits in current design and manufacturing methods. The authors show that avoiding the potential catastrophe generated by the failure of an aircraft engine relies on the prediction of the correct behaviour of microscopic imperfections. This book shows how to quantify the possibility of such failure, and that it is possible to design components that are inherently less risky and more reliable. This new, updated and significantly expanded edition gives an introduction to engine reliability and safety to contextualise this important issue, evaluates newly-proposed methods for uncertainty quantification as applied to jet engines. Uncertainty Quantification in Computational Fluid Dynamics and Aircraft Engines will be of use to gas turbine manufacturers and designers as well as CFD practitioners, specialists and researchers. Graduate and final year undergraduate students in aerospace or mathematical engineering may also find it of interest.
Computational Fluid Dynamics In Practice
DOWNLOAD
Author : Norman Rhodes
language : en
Publisher: John Wiley & Sons
Release Date : 2001-08-22
Computational Fluid Dynamics In Practice written by Norman Rhodes and has been published by John Wiley & Sons this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001-08-22 with Science categories.
Papers from a recent seminar discuss challenging applications in computational fluid dynamics (CFD) and identify techniques which are likely to occur in the next generation of codes. Specific topics include numerical accuracy in CFD, comparison of a conventional RANS and a lattice gas dynamics simulation, the validation of rapid CFD modeling for turbomachinery, and numerical determination of windage losses on high-speed rotating discs. Other subjects include using CFD to investigate combustion in a cement manufacturing process, validation of the coal combustion capability in the star-CD code, blast wave simulation, and built environments using CFD. Rhodes is chairman of the Institution of Mechanical Engineers' Energy Transfer and Thermofluid Mechanics Group. Distributed by ASME. c. Book News Inc.
Computational Modelling Of Two Phase Air Oil Flow Within An Aero Engine Bearing Chamber
DOWNLOAD
Author : M. B. Farrall
language : en
Publisher:
Release Date : 2001
Computational Modelling Of Two Phase Air Oil Flow Within An Aero Engine Bearing Chamber written by M. B. Farrall and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2001 with Fluid mechanics categories.
Frontiers In Applied Mechanics
DOWNLOAD
Author : Zishun Liu
language : en
Publisher: World Scientific
Release Date : 2014-11-20
Frontiers In Applied Mechanics written by Zishun Liu and has been published by World Scientific this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-11-20 with Technology & Engineering categories.
Frontiers in Applied Mechanics is a compilation of cutting-edge research in applied mechanics by 65 of the world's leading researchers and academics. It comprises current new research directions and topics in the field, as well as developments in the classical branches of applied mechanics; namely solid mechanics, fluid mechanics, thermodynamics, and materials science. Frontiers in Applied Mechanics also includes contributions from new emerging areas such as nanomechanics, biomechanics, electromechanics, the mechanical behavior of advanced materials, mechanics of soft materials, and many other inter-disciplinary research areas in which the concepts of applied mechanics are extensively applied and developed. The mathematical modeling and methodology for applied mechanics are also included, with applications to many interesting mechanics aspects. All articles were carefully selected following a thorough review process by peers.The aim of this collection is to contribute to knowledge in all aspects of applied mechanics; to improve the reader's understanding of the topics and aid their corresponding advances in the field. Readers may also use the contents as a guide for future research directions.
Untersuchung Der Lversorgung In Einer Triebwerkstypischen Lagerkammer Mittels Experimenteller Und Numerischer Methoden
DOWNLOAD
Author : Matthias Krug
language : de
Publisher: Logos Verlag Berlin GmbH
Release Date : 2019-07-15
Untersuchung Der Lversorgung In Einer Triebwerkstypischen Lagerkammer Mittels Experimenteller Und Numerischer Methoden written by Matthias Krug and has been published by Logos Verlag Berlin GmbH this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019-07-15 with Technology & Engineering categories.
Der Bedarf an effizienteren und emissionsarmen Flugzeugtriebwerken führt aufgrund der hierzu notwendigen steigenden Wellendrehzahl zu einer stetig wachsenden thermischen und mechanischen Belastung der eingesetzten Wälzlager. Die Bereitstellung einer robusten Ölversorgung zur Schmierung und vor allem Kühlung der Wälzkörper, welche in der Regel über einen Freistrahl zum Rotor beziehungsweise Lager realisiert wird, ist daher unerlässlich für den zuverlässigen und sicheren Betrieb eines solchen Flugzeugtriebwerks. Um dem wachsenden Bedarf an mehr Kühl- beziehungsweise Schmiermittel gerecht zu werden, ist eine optimierte Ölzuführung und ein somit effizienteres Ölsystem vonnöten. Daran schließt die vorliegende Arbeit an. Mittels einer umfassenden experimentellen Untersuchung einer Ölzuführung via Freistrahl zum Triebwerkskugellager erfolgt die Identifizierung der Einflussgrößen einer solche Zuführung. Zusätzlich werden deren Auswirkung auf die Effizienz der Ölversorgung analysiert. In dieser Arbeit wird nachgewiesen, dass diese Einflussgrößen über einen Parameter zusammengefasst werden können, um die Auslegung einer Ölversorgung eines Triebwerkskugellagers zu bewerten. Unterstützt wird dieser Nachweis durch begleitend durchgeführte numerische Simulationen der vorliegenden Ölversorgung mittels der Volume of Fluid Methode (VoF), welche sich als geeignete Methode für die numerische Vorhersage der Ölversorgungseffizienz erweist.
Analysis Of The Oil Film On A Bearing Chamber Housing
DOWNLOAD
Author : J. W. Chew
language : en
Publisher:
Release Date : 1996
Analysis Of The Oil Film On A Bearing Chamber Housing written by J. W. Chew and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1996 with Fluid mechanics categories.