Validation of an air temperature gradient using computational flfl uid dynamics in a semi-open type greenhouse and determination of kimchi cabbage physiological responses to temperature differences

Vegetable crops production in the fi eld and changes in physiological aspects of crops during the growing season may beaff ected by the increased temperatures associated with climate change. The objectives of this research were to evaluatethe performance of an air temperature gradient using the computational fl uid dynamics (CFD) technique and validation ofperformance throughout Kimchi cabbage growth and physiological responses to air temperature in a greenhouse temperaturegradient (GTG). We simulated temperature diff erences with CFD in a semi-closed plastic tunnel, which is a GTG. Theaccuracy of CFD improved by vertical and horizontal temperature profi les was evaluated for the performances of a GTG. Thegrowth of Kimchi cabbage was examined and validated using a temperature gradient within a GTG. Correlation coeffi cientsof measured heights were 1.120, 0.597, and 0.459. Root mean square error was below 0.103, which means the CFD simulationvalues were highly accurate. The error analysis showed that it was possible to accurately predict temperature gradientchanges within a GTG using CFD techniques. CFD results showed an average error of 0.597 °C compared to fi eld monitoringresults. The maximum temperature diff erence of the GTG was 5.7 °C, suggesting a well-controlled set point (6 °C diff erencebetween outside conditions and inside conditions of the GTG). On a cloudy day, the GTG set diff erential temperature(dT) was well maintained, while the accuracy of the GTG’s dT was degraded on sunny days because of interference by solarradiation. There was a signifi cant diff erence in the growth, net photosynthetic rate, transpiration rate, and intercellular CO 2concentration along with temperature diff erences in the GTG. CFD can simulate temperature gradient distribution in a GTGand predict the temperature diff erence for equipment with diff erent specifi cations. These facilities can be used in climatechange-related studies, such as assessment of crop production area optimization, crop physiological response to temperature,vulnerability assessment of crop production under increasing temperatures, or extreme weather. KCI Citation Count: 0