Browsing Turbomachinery and Pump Symposia by Author "Nicholas, John C."
Now showing items 1-14 of 14
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Nicholas, John C.; Edney, Stephen L.; Matthews, Terryl; Varela, Francisco J. Mourente (Texas A&M University. Turbomachinery Laboratories, 2001)A 16 megawatt ethylene drive steam turbine built in 1973 experienced rub related startup vibration problems for many years. The turbine would lock into a rub as it accelerated through the rotor’s first critical speed causing ...
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Nicholas, John C.; Whalen, John K.; Franklin, Sean D. (Texas A&M University. Turbomachinery Laboratories, 1986)The importance of including flexible supports in rotordynamic analyses is discussed. Various methods of including the support in rotordynamic calculations are reviewed. A method is described in which actual compliance ...
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Operating Turbomachinery On Or Near The Second Critical Speed In Accordance With API Specifications. Nicholas, John C. (Texas A&M University. Turbomachinery Laboratories, 1989)The question of when is it safe to operate turbomachinery on or near the second critical speed is addressed. A parallel evolutionary progression of the API rotordynamic specifications and rotordynamic analysis capabilities ...
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Edney, Stephen L.; Nicholas, John C. (Texas A&M University. Turbomachinery Laboratories, 1999)Reviewed is the application of a squeeze film damper to a large steam turbine that addresses high vibration passing through the first critical speed. The turbine was the fifth near identical machine purchased over the ...
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Nicholas, John C.; Kocur, John A. (Texas A&M University. Turbomachinery Laboratories, 2005)The American Petroleum Institute (API) has recently implemented new rotordynamic stability specifications for centrifugal compressors. The specifications consist of a Level I analysis that approximates the destabilizing ...
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Selection And Design Of Tilting Pad And Fixed Lobe Journal Bearings For Optimum Turbo Rotordyanmics Nicholas, John C.; Kirk, R. Gordon (Texas A&M University. Gas Turbine Laboratories, 1979)Current trends in bearing designs for turbomachinery are reviewed in terms of manufacturing tolerances and overall design considerations. Discussion of both fixed bore and tilting pad bearings with regard to forced response ...
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Shifting Critical Speeds Out Of The Operating Range By Changing From Tilting Pad To Sleeve Bearings. Nicholas, John C.; Moll, Randall W. (Texas A&M University. Turbomachinery Laboratories, 1993)One property of heavily to moderately loaded sleeve bearings is the resulting asymmetric stiffness and damping coefficients. These asymmetric properties often result in split first critical speeds. Since the horizontal ...
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Short Course T4 On Lateral Rotordynamics of Petrochemical Equipment - Review, Examples, and Problem Kocur, John A.; Nicholas, John C. (Texas A&M University. Turbomachinery Laboratories, 2011)
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Nicholas, John C.; Edney, Stephen L.; Kocur, John A.; Hustak, Jerry F. (Texas A&M University. Turbomachinery Laboratories, 1997)The importance of correlating rotordynamic analytical results to actual test data has become extremely important in recent years. Many user specifications require the verification of vendor generated analytical results in ...
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Kocur, John A; Nicholas, John C.; Lee, Chester C. (Texas A&M University. Turbomachinery Laboratories, 2007)The evaluation of rotor system stability, which has become an essential part of rotordynamic analyses and rotating machinery design, relies heavily on the bearing and seal dynamic coefficient modeling to obtain an accurate ...
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Nicholas, John C. (Texas A&M University. Turbomachinery Laboratories, 1994)The basics of tilting pad bearing design are discussed to include limits of operation for load, speed, and metal temperature. Optimum temperature sensor locations are recommended for self-aligning and nonaligning tilting ...
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Nicholas, John C.; Wygant, Karl D. (Texas A&M University. Turbomachinery Laboratories, 1995)Reducing pivot stress, pivot wear and preventing pivot failure are major design challenges encountered by tilting pad bearing designers in the extremely high load regime where the bearing unit load may often range up to ...
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Nicholas, John C.; Elliott, Greg; Shoup, Thomas P.; Martin, Ed (Texas A&M University. Turbomachinery Laboratories, 2008)Improved turbomachinery aerodynamic performance requirements have increased journal bearing operating speeds and loads well above traditionally acceptable values. For example, for high performance gearboxes, pinion bearing ...
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Nicholas, John C. (Texas A&M University. Turbomachinery Laboratories, 2003)With performance considerations driving the design of rotating equipment, operating speeds and journal loads have increased greatly in recent years, often exceeding generally accepted design limits. In order for tilting ...