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| DOI：10.13522/j.cnki.ggps.2022157 |
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| Optimizing Geometrical Parameters of the Flow Channel in the Root-irrigation Emitters |
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ZHANG Jun, LI Lin
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1. College of Hydraulic and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, China;
2. Xinjiang Institute of Technology, Aksu 843000, China;
3. Xinjiang Key Laboratory of Hydraulic Engineering Security and Water Disasters Prevention, Urumqi 830052, China
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| Abstract: |
| 【Objective】The study is to present a new root-zone irrigation emitter and investigate the influence of the geometrical parameter of its spiral-hedge flow channel on hydraulic performance of the emitter. 【Method】The assessment is based on the variation coefficient of the design flow (Cq). Using single factor and the response surface test method, we studied experimentally how design parameters of the helical hedge flow channel affect Cq. We then established and verified a regression model to calculate the variation of Cq with operating and design parameters, from which we proposed how to optimize the flow channel parameters with minimizing Cq as the optimization objective. 【Result】The design parameters that affect Cq most are flow channel width b , the shunt angle α and number of flow channel units n. In contrast, the effect of straight section length l1, the bend radius r and the convergence section length l2 is negligible. The effect of α, b and n on Cq is confounding. With the increase in α, b and n, Cq decreases first and then increases once it reaches the minimal value. Cq varies with α, b quadratically when the operating water pressure was low or high, with their associated correlation coefficient (R2) being 0.996 7 and 0.997 1 respectively. The difference between the adjusted correlation coefficients is less than 0.2. The Cq obtained from the optimal solution for the high operating water pressure is smaller than that for the low pressure, and the relative errors between the predicted and measured Cq for the two pressure zones are 2.8% and 2.3%, respectively.【Conclusion】The regression model for variation of Cq with operating and design parameters is reliable, and the spiral hedge flow channel works better under high water pressure than under low water pressure. |
| Key words: root emitter for fruit trees; spiral hedge flow channel; geometrical parameter; hydraulic performance; response surface method |
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