A new wind vane for the measurement of atmospheric turbulence
DISCLAIMER Tfiis report was prtpared as an account of work sponsored by an agency of.the United Stam' Governma& Neither the Unitad Statcs Gov-t nor any iigtncy &exec& nor any of their employees, makes any warranty, cqrcss or impSia$ or assu~pcs any lcgal liabiity or. -responsibility for the accurae, cornplctcncss, or' ascfirltlcss of any information, 'apparatus, ~u~or~~~.orn=prtscntsthatitsuscwonLdnotinfiringeprivattlyowntdrip;hrs. product, ptoctss, or stnrict by d e name, necessarily
... cessarily COIlstitlltt or imply its endorsexxiexit,. do not ntctssarily statc or reflect those of &e . t a m Govcnuncnt ur m y agency thereof.' The Thisrtporchasbccn~p~~directiyfromthebcstavailablccopy. Available to DOE and DOE dontractors from &e office of scitntific and Tcchi;ical Jinformation, P.O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576-8401, Availabie to the public from the. n Stnricc, U.S. Department of (2mmerce, 5285 Port Royal Road, Met One 1 n s~a r . s has r e v i e w e d Matthew J. Parker's A New Wind Vane for the Measweiizent of Afmosphwk Trrbulence (U) for the completion d CRADA CR-94-010 and found that it meets &e rcquir~rnrms agrccd upon.. Mel One h m m e n t s Inc. gives its approval for the disclosure of CRADA CR-94-010 information in the a h c maolioncd publication in accordance with Article XII of Cooperative Research and Development Agreement CR-94-0 10. Executive Summary A Cooperative Research and Development Agreement (CRADA) between Met One Instruments, Incorporated (Met One) and Westinghouse Savannah River Company (WSRC) was created to develop a new wind vane that more accurately measures atmospheric turbulence. Through a process that had several phases, Met One created a prototype vane that was designed to attach to the existing Model 1585 Bi-Directional Wind Vane instrument structure. The prototype contained over 20% less mass to enhance responsiveness, which was also increased through the use of a teardropshaped fin structure. The prototype vane can be readily manufactured for commercial retail. Tests in wind tunnel of Building 735-7A, the Meteorological Engineering Facility, indicated that the new vane has a superior starting threshold of less than 0.14 meter per second, a delay distance of 0.72 meter, and a damping ratio of 0.4. The relative accuracy of less than one degree is unchanged from the previous design. The vane bias was acceptable at 0.8 degree for the horizontal wind angle, but was slightly high at 1.4 degree for the vertical wind angle. The high value of the vertical wind angle bias can most likely be reduced to the desired less than one degree value with standard manufacturing production techniques. The durability of the prototype vane was not tested in the field but is expected to be slightly less due to the use of hollow rather than foam-filled fins. However, the loss of some durability is more than compensated with increased sensitivity at low wind speeds. Field testing of the prototype is required to test for adequacy of durability. . 97x001 30.text.fmk A New Wind Vane for the Measurement of Atmospheric Turbulence (U) F'igure 1. The Met One Model 1585 3-Directional Wind Vane (multiple exposures [left] showing horizontal and vertical motiodstill [right] showing instrument with attached vane assembly) J o u d of Applied Meteombgy, Vol. 10, pp. 137-145.