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Original Articles

A Study on the Prediction of Pressure Drop in Agricultural Windbreak Nets with Diagonal Weaves

사선 방향 직조를 갖는 농업용 방풍망의 압력강하 예측 연구

Seung-Hee Kang1
,
Sung-Hyun Yum2*
강 승희1
,
염 성현2*
1Professor, Department of Aerospace Engineering, College of Engineering, Jeonbuk National University, Jeonju 54896, Korea
2Researcher, Protected Horticulture Research Institute, National Institute of Horticultural and Herbal Science, R.D.A., Haman 52054, Korea
1전북대학교 항공우주공학과 교수
2농촌진흥청 국립원예특작과학원 시설원예연구소 연구사
*Corresponding Author
31 October 2025. pp. 496-504
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Abstract

This study investigates the engineering applicability of a method for predicting the pressure drop across agricultural windbreak nets with diagonal weave patterns. The blockage rate of the nets is determined using an image processing technique and then applied it to the Idel’chik’s formula. The predictions using the Idel’chik formula showed good agreement with wind tunnel test data, particularly for nets with a low blockage rate at low wind speeds. The airflow passing through the nets generally exhibited a pressure drop proportional to the square of the wind speed. However, a steep increase in pressure drop was observed for nets with a high blockage rate, whereas those with a low blockage rate showed a more gradual increase. The pressure loss coefficient tended to increase as velocity decreased at low speeds, while it converged to a constant value at wind speeds above 5 m·s-1. To improve the predictive accuracy of the Idel’chik’s formula, especially for nets with diverse weave patterns and high blockage rates, further research is required. This should include experiments on various weave patterns and additional consideration of factors such as thread twist and net deformation.

Keywords
blockage rate
Idel’chik method
image processing
wind tunnel test

망 격자 내부에 사선 방향 직조 패턴이 포함된 농업용 방풍망에 대하여 영상이미지 처리 기법으로 폐쇄율을 구하고 이를 Idel’chik 경험식에 적용하여 압력강하 예측 방법의 공학적 유용성을 확인하였다. Idel’chik 경험식에 의한 예측 결과와 풍동시험 결과를 비교하여 낮은 폐쇄율을 갖는 경우 낮은 풍속에서는 매우 정확한 예측 결과를 보임을 확인할 수 있었다. 또한 방풍망을 통과하는 흐름은 풍속의 제곱에 비례하는 압력강하 특성을 보이지만 높은 폐쇄율을 갖는 방풍망의 경우 급격한 압력강하가 발생되는 반면 낮은 폐쇄율의 방풍망은 풍속에 따른 압력강하가 상대적으로 완만하게 발생됨을 확인할 수 있었다. 방풍망의 손실계수는 저속에서는 속도가 감소함에 따라 증가하는 경향을 보였으며 5m·s-1 이상에서는 풍속이 증가할수록 일정한 값에 수렴해 가는 경향을 보였다. Idel’chik 경험식이 다양한 직조 패턴 및 높은 폐쇄율을 갖는 방풍망 그룹까지 정확한 압력강하를 예측하기 위해서는 다양한 직조 패턴에 대한 실험과 실의 꼬임 정도와 망의 변형 등에 대한 추가적인 연구가 필요할 것으로 판단된다.

키워드
Idel’chik 방법
영상이미지 처리
폐쇄율
풍동시험
References
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Information
  • Publisher :The Korean Society for Bio-Environment Control
  • Publisher(Ko) :(사)한국생물환경조절학회
  • Journal Title :Journal of Bio-Environment Control
  • Journal Title(Ko) :생물환경조절학회지
  • Volume : 34
  • No :4
  • Pages :496-504
  • Received Date : 2025-09-29
  • Revised Date : 2025-10-22
  • Accepted Date : 2025-10-24
  • DOI :https://doi.org/10.12791/KSBEC.2025.34.4.496
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