工作喷嘴带直管段的新型喷射器性能数值模拟研究

Numerical simulation study on the performance of a new ejector with working nozzle and a straight tube section

针对喷射器效率偏低的问题,基于引射喷管工作原理,提出了工作喷嘴末端加入直管段的新型喷射器,采用计算流体动力学(CFD)技术,探究了新型喷射器的流场演化规律和性能,研究了结构参数对喷射器性能的影响。结果表明,在相同工作参数下,直管段的设计可以有效提高喷射器引射率,增大喷射器卷吸引射流体的能力。当直管段长度为10 mm时,引射率为0.593,提升率为17.43%,改变混合室尺寸可以使得喷射器性能最优时的引射流体流量增大17.5%~30.2%;新型喷射器性能较传统喷射器更稳定,且效率更高、高效工作范围更大。

For the problem of low efficiency of ejectors,a straight tube section was added to the end of the working nozzle based on the Pilot nozzle,and the flow field evolution law and performance of the new ejector were explored by computational fluid dynamics technology(CFD),and the influence of structural parameters on the performance of the ejector was studied.The results show that under the same working parameters,the design of the straight tube section can effectively improve the mass entrainment ratio and increase the ability of the ejector to attract jet fluid.When the length of the straight pipe section is 10 mm,the mass entrainment ratio is 0.593,the lifting rate is 17.43%,and the flow rate of the ejector can be increased by 17.5%~30.2%when the size of the mixing chamber is changed.The new ejector is more stable,having higher efficiency and a larger operating range than conventional ejectors.