喷嘴结构对水喷射泵抽气效率影响的数值研究

Impact of Nozzle Structure on Efficiency of Water Jet Pump:A Simulation Study

采用FLUENT计算软件,对渐缩型喷嘴和孔口型喷嘴水喷射泵内气液两相流动过程进行了数值模拟。比较了相同工况下两种喷嘴结构水喷射泵的抽气特性,并对水喷射泵内部的水相百分数、速度、湍流动能分布进行了分析。结果表明,在相同工况下,孔口型喷嘴抽吸气体的性能优于渐缩型喷嘴的抽气性能。孔口型喷嘴形成的射流结构有利于与气相的能量交换和组分混合,渐缩型喷嘴的湍流分布不利于能量交换,大量的能量耗散是其抽吸气体效率下降的主要原因。对水喷射泵内部两相流动过程进行数值模拟分析,不仅可以加深水喷射泵抽气机理的理解,还为水喷射泵的抽气效率提高和优化设计提供了一定的参考。

The dynamics of gas/liquid flow fields in the water jet pump,with convergent and/or orifice nozzls, was mathematically modeled,theoretically analyzed and numerically simulated with the software Fluent.The impact of the convergent and orifice nozzles on the percentage,velocity and turbulence kinetic energy distribution of water phase was investigated.The simulated results show that the orifice nozzle outperforms the convergent nozzlewith 30%higher pumping efficiency under the same operation conditions.For example,the orifice nozzlehas a positive impact on the energy exchange and mixing of liquid and gas phases;in contrast,the turbulence distribution genera-ted by the convergent nozzlehas a negative impact on the energy exchange,resulting in larger energy consumption and lower pumping efficiency.We suggest that the simulated results may be of some technological interest in design optimization of water jet pump.