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2025 Vol.34, Issue 3 Preview Page

Original Articles

A Study on CFD Analysis of Airflow Fan with Electric Heating Wire in Apple Orchard

사과원에서의 전기 열선 공기유동팬의 CFD 해석에 관한 연구

Sung-Hyun Yum1*
,
Sang-Cheol Choi2
,
Byeong-Gap Kim3
,
Hong-Ki Yoon4
,
Kyeong-Jin Kang5
염 성현1*
,
최 상철2
,
김 병갑3
,
윤 홍기4
,
강 경진5
1Researcher, Disaster Prevention Engineering Division, National Institute of Agricultural Sciences, Jeonju 54875, Korea
2Mechanical Clerk, Agricultural Satellite Center, National Institute of Agricultural Sciences, Jeonju 54875, Korea
3Senior Researcher, Disaster Prevention Engineering Division, National Institute of Agricultural Sciences, Jeonju 54875, Korea
4Senior Researcher, Horticulture Research Division, Chungcheongnam-do Agricultural Research and Extension Services, Yesan 32418, Korea
5Researcher, Horticulture Research Division, Chungcheongnam-do Agricultural Research and Extension Services, Yesan 32418, Korea
1국립농업과학원 안전재해예방공학과 농업연구사
2국립농업과학원 농업위성센터 공업서기
3국립농업과학원 안전재해예방공학과 농업연구관
4충청남도농업기술원 스마트농업연구과 농업연구관
5충청남도농업기술원 스마트농업연구과 농업연구사
*Corresponding Author
31 July 2025. pp. 258-267
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Abstract

To evaluate the effectiveness of the fan used to prevent frost damage in orchards, five two-staged fans with electric heating wires that could blow the horizontal wind were installed in an apple orchard measuring 896 m2 (=28 m× 32 m) with windbreak nets surrounded by on all sides. The distribution of wind speed and air temperature according to operation methods of the fan was predicted using a commercial ANSYS CFX code. The apple trees were modeled in three dimensions and the outlet wind speed and air temperature of the fan were measured for boundary conditions in a frosty apple orchard. In the cases for the heights of the fan and two combinations of its wind direction, the predictions showed that there appeared a wind speed of 0.5 m·s-1 up to 18m along tree rows and that the two-staged fan was necessary as there was a limit to the formation of airflow by applying either the upper or the lower fan. Meanwhile, as the wind blew in the direction transverse to tree rows in which the flow resistance was relatively small compared with tree rows, it has been shown that the wind of 0.9 m·s-1 affected up to 21m(=3.5 m×6 rows) and that the lower fan alone were able to form an effective airflow. The range of airflow influence was narrow, hence it was clear that the 360-degree rotating fan should be applied. Whether frost prevention by two-staged fans with electric heating wires can be effective remains an open question so that verification field tests including the investigations into the microclimates should be required. In addition, it is necessary to evaluate the effectiveness for additional heat sources due to the limit of air mixing in the upper and lower layers.

Keywords
air temperature
microclimate
windbreak net
wind speed

과원 서리 피해 예방을 위해 이용되는 전기 열선 공기유동팬의 효용성을 평가하고자 지붕형 방풍 시설이 설치된 896m2 (= 폭 28m × 길이 32m) 규모의 사과원에 수평으로 바람을 토출하는 2단(상·하단) 공기유동팬 5개를 설치하고 사과나무를 3차원으로 모델링하여 팬의 작동 방식에 따른 과원 내 풍속과 기온 분포를 상용 ANSYS CFX 코드로 전산 해석하였다. 공기유동팬의 풍속과 기온을 비닐온실과 서리가 내린 사과원에서 실측하고 CFD 해석의 경계조건으로 적용하였다. 공기유동팬의 높이(2.15m와 3.70m)와 풍향(주간 방향과 열 방향) 조합에 대하여 과원 내 풍속·기온 분포를 비교 분석한 결과, 주간 방향으로 2단 공기유동팬을 이용해 바람을 토출하는 경우 팬 출구로부터 두 번째 공기유동팬이 위치하는 18m 지점까지 0.5m·s-1 수준의 바람이 존재하는 것으로 나타났고 상단 또는 하단 공기유동팬 적용만으로는 과원 전체 기류 형성에 한계가 있는 것으로 나타났다. 반면, 유동저항이 상대적으로 작은 열 방향으로 바람이 부는 경우 21m(= 3.5m × 6칸) 지점까지 0.9 m·s-1 수준의 바람이 영향을 미치는 것으로 나타났다. 전면부로 바람을 토출하는 공기유동팬의 특성상 공기유동 영향 범위가 나무의 크기 수준에 불과하므로 과원 전체에 기류를 생성하기 위해서는 공기유동팬을 360° 회전시켜야 할 것으로 판단되었으며 공기유동팬 작동에 따른 미기상환경 조사와 함께 서리 예방을 위한 전기열원의 적정 용량 설정 및 수평 바람 토출 공기유동팬의 상·하층부 공기 혼합 한계로 인한 추가 열원에 대한 효용성 평가가 필요할 것으로 판단되었다.

키워드
기온
미기상
방풍네트
풍속
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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 :3
  • Pages :258-267
  • Received Date : 2025-10-27
  • Revised Date : 2025-06-21
  • Accepted Date : 2025-07-03
  • DOI :https://doi.org/10.12791/KSBEC.2025.34.3.258
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