Journal of Bio-Environment Control (생물환경조절학회지)

The Korean Society for Bio-Environment Control (한국생물환경조절학회)
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Analysis of Wind Velocity Profile for Calculation of Wind Pressure on Greenhouse

온실의 풍압력 산정을 위한 풍속의 수직분포 분석

  • Jung, Seung-Hyeon (Department of Agricultural Engg., Kyungpook National Univ.) ;
  • Lee, Jong-Won (Institute Agricultural Science & Technology, Kyungpook National Univ.) ;
  • Lee, Si-Young (Department of Agricultural Engg., National Academy of Agricultural Science, RDA) ;
  • Lee, Hyun-Woo (Department of Agricultural Engg., Kyungpook National Univ.)
  • 정승현 (경북대학교 농업토목공학과) ;
  • 이종원 (경북대학교 농업과학기술연구소) ;
  • 이시영 (농촌진흥청 국립농업과학원) ;
  • 이현우 (경북대학교 농업토목공학과)
  • Received : 2015.06.01
  • Accepted : 2015.07.17
  • Published : 2015.09.30
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Abstract

To provide the data necessary to determine the design wind speed for calculating the wind load acting on a greenhouse, we measured the wind speed below 10m height and analyzed the power law exponents at Buan and Gunwi. A wind speed greater than $5m{\cdot}s^{-1}$ is appropriate for calculating the power law exponent necessary to determine the wind speed distribution function according to height. We observed that the wind speed increased according to a power law function with increased height at Buan, showing a similar trend to the RDC and JGHA standards. Therefore, this result should be applied when determining the power law function for calculating the design wind speed of the greenhouse structure. The ordinary trend is that if terrain roughness increases the value of power law exponent also increases, but in the case of Gunwi the value of power law exponent was 0.06, which shows contrary value than that of the ordinary trend. This contrary trend was due to the elevations difference of 2m between tower installed and surrounding area, which cause contraction in streamline. The power law exponent started to decrease at 7 am, stopped decreasing and started to increase at 3 pm, and stopped increasing and remained constant at 12 pm at Buan. These changes correspond to the general change trends of the power law exponent. The calculated value of the shape parameter for Buan was 1.51, confirming that the wind characteristics at Buan, a reclaimed area near the coast, were similar to those of coastal areas in Jeju.

본 연구는 온실에 작용하는 풍하중 산정을 위한 설계 풍속을 결정하는데 필요한 자료를 제공하기 위하여 10m 이하 높이에서의 풍속을 측정하여 풍속고도분포지수를 산정하고 변화를 분석하였다. 고도에 따른 풍속분포함수를 결정하기 위한 풍속고도분포지수를 계산하기 위해서는 $5m{\cdot}s^{-1}$ 이상의 풍속을 사용하는 것이 타당하다고 판단된다. 농촌 개활지인 부안지역의 고도에 따른 풍속변화는 지표면으로부터 풍속이 지수함수로 증가하는 우리나라의 RDC 기준과 일본의 JGHA 기준과 잘 일치하였고 풍속고도분포지수도 0.26으로 기준들에서 제시된 0.25와 거의 동일한 값을 나타내었다. 반면 군위지역의 경우는 풍속고도분포지수가 0.06으로 산정되어 지표면조도가 클수록 풍속고도분포지수가 증가하는 일반적인 변화 경향과는 반대로 나타났다. 이는 타워가 주변지대보다 약 2m 가량 더 높은 위치에 설치되었기 때문에 유선의 급격한 변화에 의한 것으로 판단된다. 따라서 일반적으로 농촌 개활지에 설치되는 온실의 설계를 위해 적용할 풍속고도분포로는 우리나라의 RDC기준과 일본의 JGHA기준에서 제시한 풍속고도분포가 가장 타당한 것으로 사료된다. 부안의 경우 오전 7시 경부터 풍속고도 분포지수가 감소하다가 오후 3시경에 최소가 된 후 다시 증가하여 24시경에 일정해지는 것으로 나타나 시간에 따른 풍속고도분포지수의 일반적인 변화경향과 잘 일치하였다. 부안지역은 형상변수가 1.51로 나타나 간척지인 부안지역의 풍속특성이 제주도 연안지역과 유사한 풍속특성을 가지고 있음을 확인하였다.

Keywords

References

  1. Al-Abbadi, N.M. and S. Rehman. 2009. Wind speed and wind power characteristics for Gassim, Saudi Arabia. Int'l J. Green Energy 6(2):201-217. https://doi.org/10.1080/15435070902785068
  2. Architectural Institute of Japan (AIJ). 2004. Recommendations for loads on buildings.
  3. Architectural Institute of Korea (AIK). 2009. Korean building code and commentary (in Korean).
  4. Capps, S. B. and Zender, C. S. 2008. Observed CAM3 GCM sea surface wind speed distributions: characterization, comparison, and bias reduction. J. Climate, 21(24):6569-6585. https://doi.org/10.1175/2008JCLI2374.1
  5. Choi, M.G., S.W. Yun, H.T. Kim, S.Y. Lee and Y.C. Yoon. 2014. Current status on the greenhouse foundation. Journal of Agriculture & Life Science 48(3):251-260 (in Korean). https://doi.org/10.14397/jals.2014.48.3.251
  6. Clobes, M., A. Willecke and U. Peil. 2011. Shape-dependent characteristics of full-scale wind profiles. J. Wind Engg. and Ind. Aerodyn. 99(9):919-930. https://doi.org/10.1016/j.jweia.2011.05.005
  7. Davenport, A.G. 1960. Rationale for determining design wind velocities. J. Struct. Engg. ASCE86:39-68.
  8. Farrugia, R.N. 2003. The wind shear exponent in a Mediterranean island climate. Renewable Energy 28(4):647-653. https://doi.org/10.1016/S0960-1481(02)00066-6
  9. Gualtieri, G. and S. Secci. 2011. Wind shear coefficients, roughness length and energy yield over coastal locations in southern Italy. Renewable Energy 36(3):1081-1094. https://doi.org/10.1016/j.renene.2010.09.001
  10. Ha, Y.C. 1998. Characteristic of wind profile according to change in ground surface roughness. Wind Engineering Institute of Korea 2(2):171-178 (in Korean).
  11. Hanafusa, T., C.B. Lee and A.K. Lo. 1986. Dependence of the exponent in power law wind profiles on stability and height interval. Atmospheric Environment 20(10):2059-2066. https://doi.org/10.1016/0004-6981(86)90348-3
  12. Japan Greenhouse Horticulture Association (JGHA), 1997. Standard for structural safety of greenhouse. Tokyo: Japan Greenhouse Horticulture Association (in Japanese).
  13. Jung, S.H., H.W. Lee, J.W. Lee, W.H. Na and S.Y. Lee. 2014a. Comparison of wind pressure calculation formula for greenhouse structure design in some nations standard. Proceedings of the Korean Society for Bio-Environment Control Conference 23(1):189-190 (in Korean).
  14. Jung, S.H., H.W. Lee, J.W. Lee, W.H. Na and S.Y. Lee. 2014b. Comparison of snow loads calculation standards for greenhouse structure design in some nations. Proceedings of the Korean Society for Bio-Environment Control Conference 23(2):169-170 (in Korean).
  15. Kim, M.K., Nam, S.W., Suh, W.M., Yoon, Y.C., Lee, S.G. and Lee, H.W. 2000. Agricultural structure engineering. Hyangmoonsa (in Korean).
  16. Kim, H.G. and J.O. Choi. 2002. Calculation of wind profile exponent in Pohang area. Wind Engineering Institute of Korea 6(1):47-52 (in Korean).
  17. Kim, H.G. 2012. Analysis on wind profile characteristics in a sublayer of atmospheric boundary layer over a semi-complex terrain. J. Env. Sci. 21(2):145-152 (in Korean).
  18. Kim, R.U., D.W. Kim, K.C. Ryu, K.S. Kwon, and I.B. Lee. 2014. Estimation of wind pressure coefficients on even-span greenhouse built in reclaimed land according to roof slope using wind tunnel. Protected Horticulture and Plant Factory. 23(4):269-280 (in Korean). https://doi.org/10.12791/KSBEC.2014.23.4.269
  19. Ko, J.W., Quan, H.C. and Lee, B.G. 2012. The study on assessment of roughness coefficient for designing wind farm in Jeju island. J. Korean Society for Geo-Spatial Information System 20(2):15-22 (in Korean).
  20. Kwon, D.K. and A. Kareem. 2013. Comparative study of major international wind codes and standards for wind effects on tall buildings. J. Engg. Struct. 51:23-35 https://doi.org/10.1016/j.engstruct.2013.01.008
  21. Lassig, J.L., M.G. Cogliati, M.A. Bastanski and C. Palese. 1999. Wind characteristics in Neuquen, north Patagonia, Argentina. J. Wind Engg. and Ind. Aerodyn. 79(1-2):183-199. https://doi.org/10.1016/S0167-6105(98)00110-X
  22. Lee, B.G., S.J. Moon, and J.W. Ko. 2013. Power law exponent in coastal area of northeastern Jeju island for the investigation of wind resource. J. Korean Society for Geo-Spatial Information System 21(4):65-71 (in Korean).
  23. Li, Q.S., L. Zhi and F. Hu. 2010. Boundary layer wind structure from observations on a 325m tower. J. Wind Engg. and Ind. Aerodyn. 98(12):818-832. https://doi.org/10.1016/j.jweia.2010.08.001
  24. Liu, H. 1990. Wind Engineering - A handbook for structural engineers.
  25. Ministry of Agriculture, Food and Rural Affairs (MAFRA). 1999. Greenhouse structure design standards and explanations (in Korean).
  26. Ministry for Food, Agriculture, Forestry and Fisheries(MIFAFF), Rural Development Administration(RDA). 2010. Designated notice of standards to endure disaster for horticultural and special facilities (in Korean).
  27. National Greenhouse Manufactures Association (NGMA). 2004. Structural design manual. ed. NGMA, PA, USA.
  28. Netherlands Standardization Institute (NEN). 2004. Greenhouses : Design and construction - Part1 : Commercial production greenhouses.
  29. Peil, U. and G. Telljohann. 1999. A wind turbulence model based on long-term measurements. Wind Engineering into The 21st Century - Proceedings of The 10th International Conference on Wind Engineering. Copenhagen, Denmark, 147-153.
  30. Pryor, S. and R. Barthelmie. 2009. Historical trends in nearsurface wind speeds. Indiana University Press. In Understanding Climate Change, chapter 15:169-183.
  31. Ro, K.S. and P.G. Hunt. 2007. Characteristic wind speed distributions and reliability of the logarithmic wind profile. J. Env. Engg. 133(3):313-318. https://doi.org/10.1061/(ASCE)0733-9372(2007)133:3(313)
  32. Rural Development Corporation(RDC). 1995. Greenhouse structural requirements. ed. RDC, Uiwang, Korea (in Korean).
  33. Sen, Z., A. Altunkaynak and T. Erdik, 2012. Wind velocity vertical extrapolation by extended power law. Advances in Meteorology. 2012:Article ID 178623.
  34. Smith, K., G. Randall, D. Malcolm, N. Kelly and B. Smith. 2002. Evaluation of wind shear patterns at Midwest wind energy facilities. American Wind Energy Association(AWEA) WindPower 2002 Conference, Portland, OR (US)