%0 Journal Article
%A WANG  Ya-lin
%A WU  Yu-xin
%A ZHU  Shi-jiang
%A ZHAO  Shu-jun
%A XIA  Dong
%T Effect of End Face Inclination Angles of Emitters on Local Head Loss in Drip Irrigation Pipes
%D 2025
%R 10.11988/ckyyb.20240207
%J Journal of Changjiang River Scientific Research Institute
%P 138-146
%V 42
%N 5
%X <p id="p00005"><strong>[Objective]</strong> Taking inline cylindrical emitters as the research object, this study modifies the inclination angle of the emitter’s sidewall end face to investigate the effects of structural optimization on local head loss in drip irrigation pipes. <strong>[Methods]</strong> The end faces of the inline cylindrical emitters were structurally optimized, with inclination angles set as explanatory variables at four levels: 15°, 30°, 45°, and 90°. Irrigation experiments and numerical simulations were conducted, and the results were processed using the principle of dimensional homogeneity and multiple regression analysis. <strong>[Results]</strong> The results showed that the velocity and pressure gradients in the convergent and divergent sections of the drip irrigation pipe decreased as the inclination angle of the emitter end face decreased. Based on the principle of dimensional homogeneity and multiple regression analysis, a calculation model for local head loss in drip irrigation pipes incorporating the inclination angle of emitter end face was established. The local head loss was found to be inversely proportional to the 0.706 power of the cotangent of the inclination angle. Case analysis demonstrated that for a 60-m drip irrigation pipe with 0.6-m emitter spacing, the local head loss at inclination angles of 15°, 30°, and 45° decreased to 26.0%, 44.7%, and 65.0% of that at 90°, respectively. For a 60-m drip pipe with 1-m emitter spacing, the local head loss at inclination angles of 15°, 30°, and 45° decreased to 29.6%, 48.1%, and 74.1% of that at 90°, respectively. <strong>[Conclusion]</strong> In conclusion, the inclined design of the emitter’s end face can significantly reduce local head loss in drip irrigation pipes. Considering manufacturing complexity and cost, an inclination angle of 15° is recommended. These findings can provide references for drip irrigation design and pipe network optimization.</p>
%U http://ckyyb.crsri.cn/EN/10.11988/ckyyb.20240207