Journal of The Korean Society of Agricultural Engineers (한국농공학회논문집)

The Korean Society of Agricultural Engineers (한국농공학회)
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Evaluation of Wind Load and Drag Coefficient of Insect Net in a Pear Orchard using Wind Tunnel Test

풍동실험을 통한 배과원 방충망의 풍하중 및 항력계수 평가

  • Received : 2018.09.10
  • Accepted : 2018.10.30
  • Published : 2019.01.31
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Abstract

Fruit bagging is a traditional way to produce high-quality fruit and to prevent damage from insects and diseases. Growing pears by non-bagging is concerned about the damage from insect, it can be controlled by installing a insect net facility. Wind load should be considered to design the insect net facility because it has the risk of collapse due to the strong wind. So we carried out wind tunnel test for measurement of drag force, where the insect net with porosity about 65% is selected as an experimental subject. As a result of the test, drag force was measured to be 244.14 N when insect net area and wind speed are $1m^2$ and 22.7 m/s respectively. And, drag coefficients for the insect net were found to be about 0.55~0.57, which may be used as the preliminary data to design the insect net facilities at the orchard.

Keywords

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Fig. 1 Test bed for the insect net facility at Pear Research Station, Naju, Korea

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Fig. 2 Detailed shape and size of the in sect net used inthe wind tunnel test

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Fig. 3 Overview and main parts of the wind tunnel

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Fig. 4 Wind speed vertical profile at wind tunnel

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Fig. 5 Diagram of wind tunnel test setup

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Fig. 6 Wind tunnel test setup

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Fig. 7 Wind speed of windward in baffle plate vs. Fan speed of wind tunnel

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Fig. 8 Shape change of 1 ㎡ insect net by wind speed

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Fig. 9 Results of measuring load of insect net by swept area

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Fig. 10 Drag force by swept area of insect net

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Fig. 11 Drag force by wind speed

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Fig. 12 Drag coefficient by swept area

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Fig. 13 Drag coefficient by wind speed

Table 1 Specifications of the wind tunnel located at National Agricultural Institute Sciences (NAS), Jeonju, Korea

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Table 2 Results of wind tunnel test according to connection methods between load cells and insect net

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Table 3 Wind load of insect net according to wind speed and swept area

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Table 4 Drag coefficient of insect net according to wind speed and swept area

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References

  1. Castellano S., G. Scarascia Mugnozza, G. Russo, D. Briassoulis, A. Mistriotis, S. Hemming, and D. Waaijenberg, 2008. Plastic nets in agricultural: A general review of types and applications. Applied Engineering in Agriculture 24(6): 799-808 (in Korean). doi:10.13031/2013.25368.
  2. Castro, I. P., 1971. Wake characteristics of two-dimensional perforated plates normal to an air-stream. Journal of Fluid Mechanics 46(3): 599-509. doi:10.1017/S0022112071000727.
  3. Kim, S. H., 1999. Studies on the development of prevention technology of disasters and labor saving cultural practice in Pear. Ministry of Agriculture and Forestry (in Korean).
  4. Kim, Y. M., J. G. Jeon, and K. P. You, 2006. Wind tunnel experiment about effect of protection against wind according to the variation porosity of wind fence. Journal of the Architectural Institute of Korea Structure & Construction 22(2): 91-97 (in Korean). doi:10.1007/s00254-008-1219-y.
  5. Kim, W. S., 2013. Selection of suitable cultivars for processing and development on cost reduction of production in Asian Pear, 4. Rural Development Administration (RDA) (in Korean).
  6. Kwon, S. D., D. H. Kim, S. H. L, and H. S. Song, 2011. Design criteria of wind barriers for traffic. Part 1: wind barrier performance. Wind and Structures 14(1): 55-70. doi:10.12989/WAS.2011.14.1.055.
  7. Lee, S. G., 1995. Greenhouse structural requirements, Rural Development Corporation of Korea (in Korean).
  8. Ministry of the Interior and Safety (MOIS), 2009-2018. Statistical yearbook of natural disaster (in Korean).
  9. Shim, K. M., M. S. Kim, Y. S. Kim, M. P. Jung, H. Hwang, and S. C. Kim, 2013. Meteorological analysis of installation effects of a windbreak net on reducing wind speed at an apple orchard. Korean Journal of Agricultural and Forest Meteorology 15(4): 298-303 (in Korean). doi:10.5532/KJAFM.2013.15.4.298.
  10. Statistics Korea (KOSTAT), 2015. Agriculture, Forestry & Fishery Census Report (in Korean).
  11. Yim, S. H., K. S. Cho, J. H. Choi, J. H. Lee, U. Y. Lee, H. J. Seo, B. L, and S. S. Kang. 2017. Characteristics of non-bagging pear fruit according to cultivars of different ripening time and fruit skin color. Horticultural Science Technology 35(1): 125 (in korean).
  12. You, K. P., 2005. Wind tunnel experiment about effect of protection against wind according to the variation porosity of wind fence. Journal of the Architectural Institute of Korea Structure & Construction 21(4): 109-116 (in Korean).
  13. You, K. P., J. Y. You, and Y. M. Kim, 2009. Effect of wind Fences in reducing wind velocity at fruit farms. Journal of the Architectural Institute of Korea Structure & Construction 25(2): 99-106 (in Korean).
  14. Yum, S. H., K. J. Kwon, S. H. Sung, and Y. D. Choi, 2007. The installation effect and optimal pipe sizes of an anti-wind net by computational analysis. Journal of Biosystems Engineering 32(6): 430-439 (in Korean). doi:10.5307/JBE.2007.32.6.430.
  15. Yum, S. H., and S. H. Kang, 2013. An experimental study on characteristics of pressure drop of screens used in horticultural facilities. Journal of the Korean Society of Agricultural Engineers 55(6): 31-35 (in Korean). doi:10.5389/KSAE.2013.55.6.031.
  16. Yum, S. H., S. H. Kang, S. H. Kim, S. B. Lee, and M. Y. Kim, 2011. Effects of an anti-wind net on wind velocity reduction by a wind tunnel test and CFD. Journal of Biosystems Engineering 36(5): 355-360 (in Korean). doi:10.5307/JBE.2011.36.5.355.