Browsing by Author "Vance, John M."
Now showing items 1-20 of 33
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Gamal Eldin, Ahmed Mohamed (Texas A&M University, 2004-09-30)This thesis presents numerical predictions for the leakage and direct stiffness coefficients of pocket damper seals. Modifications made to earlier flow-prediction models are discussed. Leakage and static pressure measurements ...
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Childs, Dara W.; Vance, John M. (Texas A&M University. Turbomachinery Laboratories, 1997)The possible negative or positive impact of annular seal on rotordynamics of compressors and steam turbines is discussed. The nature of destabilizing forces that can be developed by "seethrough" and interlocking labyrinths ...
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Bulk-Flow analysis for force and moment coefficients of a shrouded centrifugal compressor impeller Gupta, Manoj Kumar (Texas A&M University, 2005-08-29)An analysis is developed for a compressible bulk-flow model of the leakage path between a centrifugal compressor's impeller shroud and housing along the front and back side of the impeller. This is an extension of analysis ...
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Wiesenborn, Robert Kyle (Texas A&M University, 2007-04-25)Magnetic bearings use variable attractive forces generated by electromagnetic control coils to support rotating shafts with low friction and no material wear while providing variable stiffness and damping. Rotor deflections ...
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Venugopal, Arvind Madabushi (Texas A&M University, 2005-02-17)This research deals with the comparison of fault signatures in induction motors. The primary objective is to study and analyze the similarities in the electrical and mechanical fault signatures, and to determine the ...
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Vance, John M.; Murphy, Brian T.; Tripp, Harley A. (Texas A&M University. Turbomachinery Laboratories, 1984)As a result of a continuing demand for increased performance, modern turbomachines are sometimes designed to operate near a critical speed. Machines for petrochemical and natural gas service have been purchased and delivered ...
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Zeidan, Fouad Y.; Andres, Luis San; Vance, John M. (Texas A&M University. Turbomachinery Laboratories, 1996)There are common misconceptions and occasional misapplications associated with squeeze film dampers. The authors have worked for more than 25 years researching, experimenting, and applying this subject matter to all types ...
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Kannan Srinivas, Bharathwaj (Texas A&M University, 2004-09-30)Experiments conducted at the Texas A&M Turbomachinery Laboratory and field applications have shown that pocket damper seals (PDS) can be used to suppress vibrations in compressors. A mathematical model is presented for the ...
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Kar, Rahul (Texas A&M University, 2005-11-01)Rotordynamic instability can be disastrous for the operation of high speed turbomachinery in the industry. Most ??instabilities?? are due to de-stabilizing cross coupled forces from variable fluid dynamic pressure around ...
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Schomerus, Aaron Michael (2009-05-15)Torsional vibration can be characterized as the cyclic variation of shaft speed, which can cause various failures in rotating machines, such as: gear-tooth breakage, blade-off due to blade fatigue in steam turbines, break-off ...
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Emery, Michael Aaron (Texas A&M University, 2007-04-25)This thesis focuses on the torsional-lateral interactions seen in gear coupled rotors. Of particular interest are cases where the torsional stiffness parameters affect the lateral critical speeds and where lateral stiffness ...
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Vance, John M.; Palazzolo, Alan B.; Zeidan, Fouad Y. (Texas A&M University. Turbomachinery Laboratories, 1987)Electrical damage to turbomachinery parts has caused a number of machinery failures and many hours of costly downtime. The problem of electrical voltages and currents being generated in non-electrical machines has puzzled ...
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Choudhry, Vivek Vaibhav (Texas A&M University, 2004-11-15)Wire mesh vibration dampers have been the subject of some very encouraging experiments at the Texas A&M Turbomachinery laboratories for the past several years and have emerged as an excellent replacement for squeeze film ...
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Jones, Adam Matthew (2009-06-02)Wire mesh dampers are under investigation because they are seen as replacements for squeeze film dampers as a source of direct stiffness and damping at bearing locations. There are several advantages of wire mesh dampers ...
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Rodriguez Colmenares, Luis Emigdio (Texas A&M University, 2004-09-30)This thesis provides experimental frequency dependent stiffness and damping coefficient results for a high-speed, lightly loaded, flexible-pivot tilting-pad bearing, with a load-on-pad configuration. Test conditions include ...
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Breedlove, Anthony Wayne (2009-06-02)This thesis presents further experimentation and modeling for bump-type gas foil bearings used in oil-free turbomachinery. The effect of shaft temperature on the measured structural force response of foil bearings is of ...
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Toram, Kiran Kumar (Texas A&M University, 2005-11-01)Tumble mills are hollow cylindrical shells of large diameter carrying grinding media (a combination of rock/iron ore/chemical flakes and metal balls/rods), which, upon rotation of the mill, will be ground into fine powder. ...
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Delgado-Marquez, Adolfo (Texas A&M University, 2006-04-12)Squeeze film dampers (SFDs) with low levels of external pressurization and poor end sealing are prone to air entrapment, thus reducing the damping capability. Furthermore, existing predictive models are too restrictive. ...
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Murphy, Brian T.; Vance, John M. (Texas A&M University. Turbomachinery Laboratories, 1981)A number of the computer programs for rotordynamic stability and critical speed prediction in common use during recent years have been based on the works of Myklestad, Prohl and Lund. Programs of this type, called transfer ...
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Rodrigues Rodrigues, Margarita (2009-05-15)Predictions are presented for a selected compressor using longer hole-pattern seals with L/D ratios from 0.5 to 2.5. Results were obtained for back-to-back and in-line compressors with the seal located at mid-span and at ...