Wind-Tunnel Investigation of Mass Transfer from Soil Corrugations

Abstract

Distribution of local mass-transfer coefficients over saturated corrugated surfaces was measured in a wind tunnel. Wavy (sinusoidal) surfaces were used to represent field corrugations (furrows). Visualization techniques, in conjunction with wall-pressure distribution measurements, were used to investigate the air flow pattern near the wave surface.The mass-transfer rates from various locations on a corrugated surface are intimately related with the flow structure inside the furrows. The buildup of high humidity in the vortices formed in the furrows tends to reduce the moisture transfer. These vortices are significantly more effective in reducing the evaporation loss from the bottom of deeper corrugations as compared with shallower ones. This substantiates that furrows, if deep enough, can markedly decrease moisture loss from soil.