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Wind tunnel tests of two airfoils for wind turbines operating at high reynolds numbers

Description: The objectives of this study were to verify the predictions of the Eppler Airfoil Design and Analysis Code for Reynolds numbers up to 6 x 106 and to acquire the section characteristics of two airfoils being considered for large, megawatt-size wind turbines. One airfoil, the S825, was designed to achieve a high maximum lift coefficient suitable for variable-speed machines. The other airfoil, the S827, was designed to achieve a low maximum lift coefficient suitable for stall-regulated machines. Both airfoils were tested in the NASA Langley Low-Turbulence Pressure Tunnel (LTPT) for smooth, fixed-transition, and rough surface conditions at Reynolds numbers of 1, 2, 3, 4, and 6 x 106. The results show the maximum lift coefficient of both airfoils is substantially underpredicted for Reynolds numbers over 3 x 106 and emphasized the difficulty of designing low-lift airfoils for high Reynolds numbers.
Date: June 29, 2000
Creator: Sommers, D. & Tangler, J.
Partner: UNT Libraries Government Documents Department

Roger Reynolds' Variation (1988): New Concepts of Form and Sound

Description: American composer Roger Reynolds was born on July 18, 1934, in Detroit, Michigan. At age 14, he determined to study piano after hearing a recording of Chopin's Polonaise in A-flat major, Opus 53 played by Vladimir Horowitz. Even though his piano teacher Kenneth Aiken recommended that he continue his study at the Curtis Institute of Music, Reynolds followed the suggestion from his parents that a musical career was not practical. After receiving a bachelor degree of engineering physics at the University of Michigan, he worked in the industry for a short period of time. In 1957, he returned to Michigan and resumed his study of music by taking a class called Composition for Non-Composers under the instruction of Ross Lee Finney. Reynolds continued his compositional study with Finney and Gerhard who were influenced by the Second Viennese School until he finished the master's degree (B.M. 1960, M.M. 1961). Variation was written under the auspices of The Banff Centre for the Arts in 1988. This piece was dedicated to Peter Serkin and premiered by Alec Karis, a faculty member at UCSD, on December 3, 1991 at Merkin Concert Hall, New York. This large-scale set of variations for piano is one of the rare instances in which Reynolds used a conventional genre. What concerned Reynolds most in Variation was "the notion that transformations of meaning could occur entirely as a result of changes in context." He designed this variation as five sections -capriccioso and I, grave and II, III, scorrevole and coda. Capriccioso, grave and scorrevole also refer to the three basic thematic elements of this piece. These three main themes appear throughout the whole piece employing fragmentations or superimpositions. Reynolds used two computer algorithms (SPLITZ and SPIRLZ) to make transformations on these three thematic ideas. He cut the themes up into ...
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Date: December 2003
Creator: Lee, JooHee
Partner: UNT Libraries