Effects of deflector slot/tine ratio on sprinkler spray uniformity using 3D printing technology

Abstract

In this study, sprinklers with different slot/tine ratios were manufactured using 3D printing technology, and the standard collection box experiments were conducted using sprinkler system to obtain the water flux and spray uniformity. The results show that the optimal deflector design for spray uniformity along the radius occurs at 0.15|0.45 (which means the ratio of near the axis slot width to tine width | ratio of the edge of deflector slot width to tine width) configuration, and increasing or decreasing the slot/tine ratio will reduce uniformity. The uniformity along the circumferential azimuth decreases with the increasing slot/tine ratio. The optimal configuration appears at 0.03|0.45, corresponding to a slot flow fraction of 1.89%, which is defined as the ratio of a certain slot (one of all 16 slots) flow to the total flow. With linear regression, it is found that the effect of internal slot/tine ratio on spray uniformity is higher than that of external slot/tine ratio around 50%, which is caused by the water sheet thickness and velocity. Compared with the circumferential uniformity, the total spray uniformity is more affected by the radial uniformity. Therefore, the optimal configuration for total uniformity is also 0.15|0.45, and the total standard deviation is 67% lower than that of commercial sprinkler.