Assessment of spray nozzles on water distribution on cow's surface and efficiency of water utilization by CFD

TY - JOUR

T1 - Assessment of spray nozzles on water distribution on cow's surface and efficiency of water utilization by CFD

AU - Yang, Ruimin

AU - Y. Choi, Christopher

AU - Rong, Li

AU - Zhang, Guoqiang

AU - Wang, Xiaoshuai

PY - 2024/7

Y1 - 2024/7

N2 - The spray-cooling method is used by most large-scale dairy farms currently in operation because it is regarded as one of the most effective methods for mitigating heat stress. This method, which more rapidly evaporates water sprayed onto the cow's skin surface and in so doing removes body heat by evaporative and film cooling, depends greatly on the distribution of water onto the cow's skin. The objectives we set forth in this study involved using computational fluid-dynamic simulations to assess the effectiveness (spray water-wastage rate and water distribution on the cow's body surface) of commonly used nozzles and subsequently finding a means of optimizing efficiency and water distribution during operation. Our simulations indicated that, given a traditional installation condition (the installation angle of 30° and the water flow rate of 1.3 L min−1), the average water wastage rates occurring between 9 to 25 s during spraying were 74.80 % and 80.93 % for nozzle 1 (spray angle: 135°, dispersion angle: 20°) and for nozzle 2 (spray angle: 180°, dispersion angle: 15°), respectively. The angle at which a nozzle was set had limited influence on the water wastage rate; however, when the angle was increased (from 30° to 45°), the water was not only distributed over a larger area of the skin surface but was also distributed more uniformly. When the spray direction was altered from perpendicular to parallel, the water wastage rate dropped significantly, and the rates achieved by nozzle 1 and nozzle 2 at 25 s fell by 35.72 % and 29.55 %, respectively, with the water film covering the entire back of the cow. Moreover, the water wastage rate achieved by nozzle 3 (the improved nozzle type proposed in this study), at a spray angle of 70° and a dispersion angle of 16°, was up to only 9.68 %, which was 87.99 % and 81.31 % lower than those achieved by nozzle 1 in the perpendicular and parallel spray directions, respectively. Based on our research findings, enhancing the nozzle's properties in accordance with the size of the cow's body or altering the spray direction to parallel can yield a significant improvement in water distribution on the cow's surface and water efficiency.

AB - The spray-cooling method is used by most large-scale dairy farms currently in operation because it is regarded as one of the most effective methods for mitigating heat stress. This method, which more rapidly evaporates water sprayed onto the cow's skin surface and in so doing removes body heat by evaporative and film cooling, depends greatly on the distribution of water onto the cow's skin. The objectives we set forth in this study involved using computational fluid-dynamic simulations to assess the effectiveness (spray water-wastage rate and water distribution on the cow's body surface) of commonly used nozzles and subsequently finding a means of optimizing efficiency and water distribution during operation. Our simulations indicated that, given a traditional installation condition (the installation angle of 30° and the water flow rate of 1.3 L min−1), the average water wastage rates occurring between 9 to 25 s during spraying were 74.80 % and 80.93 % for nozzle 1 (spray angle: 135°, dispersion angle: 20°) and for nozzle 2 (spray angle: 180°, dispersion angle: 15°), respectively. The angle at which a nozzle was set had limited influence on the water wastage rate; however, when the angle was increased (from 30° to 45°), the water was not only distributed over a larger area of the skin surface but was also distributed more uniformly. When the spray direction was altered from perpendicular to parallel, the water wastage rate dropped significantly, and the rates achieved by nozzle 1 and nozzle 2 at 25 s fell by 35.72 % and 29.55 %, respectively, with the water film covering the entire back of the cow. Moreover, the water wastage rate achieved by nozzle 3 (the improved nozzle type proposed in this study), at a spray angle of 70° and a dispersion angle of 16°, was up to only 9.68 %, which was 87.99 % and 81.31 % lower than those achieved by nozzle 1 in the perpendicular and parallel spray directions, respectively. Based on our research findings, enhancing the nozzle's properties in accordance with the size of the cow's body or altering the spray direction to parallel can yield a significant improvement in water distribution on the cow's surface and water efficiency.

KW - Dairy cattle

KW - Heat stress

KW - Spray cooling

KW - Spray water wastage rate

KW - Water distribution

UR - http://www.scopus.com/inward/record.url?scp=85193795457&partnerID=8YFLogxK

U2 - 10.1016/j.compag.2024.109049

DO - 10.1016/j.compag.2024.109049

M3 - Journal article

AN - SCOPUS:85193795457

SN - 0168-1699

VL - 222

JO - Computers and Electronics in Agriculture

JF - Computers and Electronics in Agriculture

M1 - 109049

ER -