Geometry effect of irrigation storage basin on particles removal efficiency: A computational fluid dynamics study

Drip irrigation requires the use of high quality water to avoid emitters clogging and the wear of hydraulic pumps and sand filters. Investing in an irrigation storage basin is not only beneficial to meet crop water requirements but also to remove naturally suspended solids by sedimentation. However, the design and sizing of an irrigation storage basin is usually based only on irrigation water needs and plant area without taking into consideration that the shape and size of the basin can also have an effect on the removal efficiency. Moreover, storage volume can be achieved by different combinations of length, width and depth. The present paper studies the effect of irrigation storage basin geometry on its performance in settling down suspended sediments. The methodology adopted in this study is based on the computational fluid dynamics using ANSYS Fluent. Specific experimental results taken from the literature are used to confirm the reliability of the numerical simulations to describe the flow field. First, a parametric study is executed in order to identify the effect of each basin dimensions. Then, trap efficiency is calculated for twenty basins having the same capacity of storage and different geometries in order to select the optimal dimensions. Results show that the removal efficiency is very sensitive to basin size, especially to its depth and length. Nevertheless, for a specific capacity of storage, two different dimensionless parameters can be used to select the optimal size: the length to depth ratio and the length to width ratio. In cases, where the depth value is required due to soil type or land surface, the second ratio can be used