TY - JOUR
T1 - CFD SIMULATION OF POROUS CANOPY HEAT TRANSFER IN APPLE ORCHARD-BASED FROST PROTECTION
AU - Hua, Weiyun
AU - Heinemann, Paul
AU - He, Long
AU - Yuan, Wenan
N1 - Publisher Copyright:
© 2023 American Society of Agricultural and Biological Engineers.
PY - 2023
Y1 - 2023
N2 - Frost events cause high economic losses in agriculture. Frost protection methods, particularly heating, have been implemented in cold-sensitive crops for millennia. Although often effective, traditional heating strategies can be insufficient or wasteful due to a lack of spatial temperature information, resulting in inadequate protection or uneven heating problems. Computational fluid dynamics (CFD) modeling has been widely used to simulate fluid flow, heat, and mass transfer by predicting various processes such as spatial flow velocity, pressure, and temperature distribution within a simulated environment. A three-dimensional CFD model for simulating airflow and heat transfer in an apple orchard was developed and validated, with the effects of heater output intensity and output velocity, heating angle, and heating duration analyzed. The validated model effectively predicted the spatial temperature changes over time inside the canopy for three representative heating schemes (heaters angled 0°, 45°, and 90° toward a tree row) with an average root mean square error (RMSE) of 2.6 °C. The simulated results show that the heating scheme of heaters angled 45° was the most effective, resulting in the largest average percentage of the protected canopy (72.3%), compared with heaters angled 0° (33.1%) and 90° (56.5%). The average percentage of the protected canopy increased by 108.2% when the heater output intensity increased to 477,000 KJ·h-1 and 46.0% when the heater output velocity increased to 15 m·s-1. However, the percentage of the protected canopy showed diminishing returns as the heater output intensity and velocity increased. The simulated heat dissipation time was linearly related to the heating duration, which can be utilized to determine the reheating time for mobile heating. The outcome of the study can be beneficial for making effective frost protection decisions in apple orchards.
AB - Frost events cause high economic losses in agriculture. Frost protection methods, particularly heating, have been implemented in cold-sensitive crops for millennia. Although often effective, traditional heating strategies can be insufficient or wasteful due to a lack of spatial temperature information, resulting in inadequate protection or uneven heating problems. Computational fluid dynamics (CFD) modeling has been widely used to simulate fluid flow, heat, and mass transfer by predicting various processes such as spatial flow velocity, pressure, and temperature distribution within a simulated environment. A three-dimensional CFD model for simulating airflow and heat transfer in an apple orchard was developed and validated, with the effects of heater output intensity and output velocity, heating angle, and heating duration analyzed. The validated model effectively predicted the spatial temperature changes over time inside the canopy for three representative heating schemes (heaters angled 0°, 45°, and 90° toward a tree row) with an average root mean square error (RMSE) of 2.6 °C. The simulated results show that the heating scheme of heaters angled 45° was the most effective, resulting in the largest average percentage of the protected canopy (72.3%), compared with heaters angled 0° (33.1%) and 90° (56.5%). The average percentage of the protected canopy increased by 108.2% when the heater output intensity increased to 477,000 KJ·h-1 and 46.0% when the heater output velocity increased to 15 m·s-1. However, the percentage of the protected canopy showed diminishing returns as the heater output intensity and velocity increased. The simulated heat dissipation time was linearly related to the heating duration, which can be utilized to determine the reheating time for mobile heating. The outcome of the study can be beneficial for making effective frost protection decisions in apple orchards.
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U2 - 10.13031/ja.15550
DO - 10.13031/ja.15550
M3 - Article
AN - SCOPUS:85168761711
SN - 2769-3295
VL - 66
SP - 825
EP - 838
JO - Journal of the ASABE
JF - Journal of the ASABE
IS - 4
ER -