偏心文丘里流量计的试验与数值模拟

Experiment and Numerical Studies on Eccentric Venturi Flow Meter

【目的】克服传统的文丘里流量计用于低压管道输水灌溉系统测流时上游侧容易产生淤积的问题。【方法】以直管段管径DN100、缩径比为0.35的偏心文丘里管为例,分别进行了实际测流试验及基于FLOW-3D的数值模拟研究,并对偏心文丘里管压力差及流出系数进行了对比分析。【结果】数值模拟的流出系数与试验流出系数基本一致,利用FLOW-3D进行偏心文丘里流量计模拟分析是可行的;偏心文丘里流量计流出系数的相对误差小于5%,能满足低压管道输水灌溉量水要求。【结论】偏心文丘里流量计在低压管道输水灌溉量水领域有较好的应用前景。

【Background】Low-pressure pipe irrigation has become increasingly popular in China,while there is a lack of flow meters suitable for measuring water flow in low-pressure pipes.【Objective】Given that traditional Venturi flow meter used for flow measurement in low-pressure pipe irrigation system is prone to silting on its upstream side,this paper presents a new eccentric Venturi flow meter to ameliorate this defect and improve measurement accuracy.【Method】A FLOW-3D numerical model was established to simulate water flow in the eccentric Venturi tube,with the straight pipe diameter DN100 and diameter reduction ratio 0.35.The model was compared with experimental measurements.【Result】The discharge coefficient calculated from the numerical model was consistent with the discharge coefficient obtained from experimental measurements,proving that the model is able to simulate water flow in the eccentric Venturi pipe.The relative error of the eccentric Venturi flow meter is less than 5%,meeting the requirements for measuring water flow in irrigation pipes.【Conclusion】The eccentric Venturi flow meter has a potential application in measuring water flow in low-pressure pipe irrigation systems.It is accurate even when water flowing in the pipes is muddy having high sediment concentration.