| 摘要: |
| 【目的】 研究文丘里管结构参数对其水力性能的影响，为文丘里施肥装置的设计提供理论依据。【方法】以进口直径为50 mm的文丘里管为研究对象，应用CFD数值计算方法，研究不同进口压力及不同进出口压力差时，文丘里收缩段锥度、喉段收缩比、喉段长度等结构参数对出口断面平均流速、管内最小压力和临界压力差等水力性能的影响。【结果】 文丘里管内最小压力发生在喉段进口环壁面处，最小压力与进出口压力差呈良好的线性关系，与收缩段锥度呈正相关关系，与喉段收缩比呈负相关关系；断面平均流速与压力差呈幂函数关系，流态指数为0.53；喉段收缩比是影响文丘里施肥器性能的主要因子，局部水头损失系数及吸肥比均与其呈负相关关系。【结论】 在设计文丘里施肥器时，应根据局部水头损失系数及吸肥比合理选择收缩比。 |
| 关键词: 文丘里管 结构参数 水力性能 |
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| 基金项目:国家科技支撑计划项目“低能耗小流量滴灌系统研发与产业化”（2007BAD38B07） |
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| Abstract: |
| 【Objective】 The effects of venturi structural parameters on its hydraulic performance were studied,which provides a theoretical basis for the design of Venturi injector.【Method】 With the inlet diameter of 50 mm,based on the method of computational fluid dynamics (CFD),the effects of Venturi structural parameters such as throat taper,throat contraction ratio and throat length on its hydraulic performance such as outlet faceted average velocity,minimum pressure and critical pressure were studied under the conditon of different inlet pressures and pressure differences between inlet and outlet.【Result】 Minimum pressure occurred in the throat inlet wall，minimum pressure and the pressure difference between inlet and outlet showed a good linear relationship，with a positive correlation between minimum pressure and its throat taper，and a negative correlation between minimum pressure and throat contraction ratio;mean velocity in outlet section and pressure difference showed a power function relationship,and the flow stance index was approximately 0.53；throat contraction ratio was the main factor affecting Venturi injector performance，with a negative relationship between coefficient of local head loss and throat contraction ratio，also between absorption fertilizer ratio and throat contraction ratio.【Conclusion】 For designing Venturi injector，contraction ratio should be reasonably selected according to the coefficient of local head loss and absorption fertilizer ratio. |
| Key words: Venturi injector structural parameter hydraulic performance |
