Load Capacity Estimation of Foil Air Journal Bearings for Oil - Free

نویسندگان

  • Christopher DellaCorte
  • Mark J. Valco
چکیده

Since its founding, NASA has been dedicated to the advancement of aeronautics and space science. The NASA Scientific and Technical Information (STI) Program Office plays a key part in helping NASA maintain this important role. The NASA STI Program Office is operated by Langley Research Center, the Lead Center for NASA's scientific and technical information. The NASA STI Program Office provides access to the NASA STI Database, the largest collection of aeronautical and space science STI in the world. The Program Office is also NASA's institutional mechanism for disseminating the results of its research and development activities. These results are published by NASA in the NASA STI Report Series, which includes the following report types: • TECHNICAL PUBLICATION. Reports of completed research or a major significant phase of research that present the results of NASA programs and include extensive data or theoretical analysis. Includes compilations of significant scientific and technical data and information deemed to be of continuing reference value. NASA's counterpart of peer-reviewed formal professional papers but has less stringent limitations on manuscript length and extent of graphic presentations. • TECHNICAL MEMORANDUM. Scientific and technical findings that are preliminary or of specialized interest, e.g., quick release reports, working papers, and bibliographies that contain minimal annotation. Does not contain extensive analysis. • CONTRACTOR REPORT. Scientific and technical findings by NASA-sponsored contractors and grantees. • TECHNICAL TRANSLATION. English-language translations of foreign scientific and technical material pertinent to NASA's mission. Specialized services that complement the STI Program Office's diverse offerings include creating custom thesauri, building customized data bases, organizing and publishing research results. .. even providing videos. Acknowledgments The authors wish to express their sincere gratitude and appreciation to Dr. Hooshang Heshmat for his experience and historical insights in the field of foil bearings and for his assistance in recommending relevant reference materials. SUMMARY This paper introduces a simple " Rule of Thumb " (ROT) method to estimate the load capacity of foil air journal bearings, which are self-acting compliant-surface hydrodynamic bearings being considered for Oil-Free turbo-machinery applications such as gas turbine engines. The ROT is based on first principles and data available in the literature and it relates bearing load capacity to the bearing size and speed through an empirically based load capacity coefficient, D. It is shown that load capacity is a linear function of bearing surface velocity and bearing projected area. Furthermore, it was found that the load capacity …

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Validation of a Three-dimensional CFD Analysis of Foil Bearings with Supercritical CO2

Foil bearings are an integral part of oil-free turbomachines which have been selected as a potential technology to enable cost efficient Supercritical Carbon Dioxide Brayton cycle for solar power application. Using high pressure CO2 as the operating fluid means that within the film Reynolds numbers in the highly turbulent regime are observed, therefore, using traditional simulation tools, such ...

متن کامل

Future Issues and Approaches to Health Monitoring and Failure Prevention for Oil-Free Gas Turbines

Recent technology advances in foil air bearings, high temperature solid lubricants and computer based modeling has enabled the development of small Oil-Free gas turbines. These turbomachines are currently commercialized as small (<100 kW) microturbine generators and larger machines are being developed. Based upon these successes and the high potential payoffs offered by Oil-Free systems, NASA, ...

متن کامل

Computational Analysis of Gas Foil Bearings Integrating 1D and 2D Finite Element Models for Top Foil

Gas foil bearings (GFBs) are finding widespread usage in oil-free turbo expanders, APUs and micro gas turbines for distributed power due to their low drag friction and ability to tolerate high level vibrations, including transient rubs and severe misalignment, static and dynamic. The static load capacity and dynamic forced performance of GFBs depends largely on the material properties of the su...

متن کامل

Foil Bearing Stiffness Estimation with Pseudospectral Scheme

Compliant foil gas lubricated bearings are used for the support of light loads in the order of few kilograms at high speeds, in the order of 50,000 RPM. The stiffness of the foil bearings depends both on the stiffness of the compliant foil and on the lubricating gas film. The stiffness of the bearings plays a crucial role in the stable operation of the supported rotor over a range of speeds. Th...

متن کامل

An Improvement in Cation Exchange Capacity Estimation and Water Saturation Calculation in Shaly Layers for One of Iranian Oil Fields

Water saturation and cation exchange capacity are the most significant parameters used to calculate a hydrocarbon zone potential. In clean formations, by applying the famous Archie model, which assumes that in the formation the only electric conductor is the formation water, the water saturation can be calculated. Additionally, in shaly sand formations this assumption may not be true as the ion...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000