CO2 Distribution under CO2 Enrichment Using Computational Fluid Dynamics Considering Photosynthesis in a Tomato Greenhouse

This study validated the CO2 distribution predicted by a computational fluid dynamics model considering CO2 absorption by photosynthesis in a chamber and greenhouse. The effect of photosynthesis with CO2 emission from a perforated tube remains not fully understood, although previous studies on CO2 distribution in greenhouses have been conducted. Moreover, comparisons between CO2 concentration measurement and simulation were obtained in the chamber and greenhouse model. Cases with open and closed side vents of the greenhouse showed that closed side vents have slightly more even of CO2 concentration than those with open side vents inside the greenhouse. In contrast, the coefficient of variance (CV) of CO2 inside the plant, open (8.8%) and closed (8.7%) side vents, induced almost no significant improvement. Additionally, cases of a rainy- and sunny-day model showed that photosynthetically active radiation possibly compensated CO2 absorption through photosynthesis to be low at low light (rainy day) and higher at high light (sunny day). Nonetheless, the variability of CO2 concentration inside the plant between rainy and sunny days determined almost no significant difference. Thus, this research shows characteristics of CO2 distribution, assessing photosynthesis and the variability of CO2 concentration that leads to the efficiency of CO2 enrichment in the greenhouse.