Numerical Study on Improving Uniformity of Airflow in Newly Developed Photosynthetic Chamber

Abstract

A numerical simulation was performed to predict the distribution and uniformity of the airflow in a newly developed photosynthesis chamber. It is a semi-closed hanging-type chamber with three exhaust fans placed at the top to maintain airflow. The chamber's bottom (area: 0.55 m²) is fully opened for outside air inflow. For model validation, we measured both horizontal and vertical air velocity inside the chamber. After model validation, multiple sizes of transparent plates were applied just below the top of the chamber to investigate the effect of the plates on the uniformity of airflow. The simulation's results showed a diminishing stagnant area at the higher part of the plant, reaching a more uniform airflow distribution, with a Coefficient of Variation (CV) of 9.1% (full plate), 12.2% (half plate placed near the fans), 50.9% (without a plate), 45.5% (half plate placed on the opposite side of the fans), and 44.0% (small plate placed opposite with the fans). From simulation results, mounting a full-size transparent plate and a half-size one near the fans can significantly help to produce uniformair velocity distribution at the plant canopy.