含稀相粒子的纳米燃油喷雾特性模拟研究

In order to explore the influence of dilute-phase nano-heterogeneous particles on the spray characteristics of fuel jets, based on the visualization test results of nano-fuel sprays, a fuel spray model containing dilute-phase nano-particles was established using computational fluid dynamics software. The accuracy of the model was verified according to the test results, and the effects of injection pressure, ambient temperature and particle mass concentration on the spray characteristics of CeO₂ nano-fuel were studied through this model. The research results show that: under the same injection pressure and at different spray development times, the spray penetration distance and Sauter mean diameter (SMD) of nano-fuel are larger than those of diesel, and the spray cone angle is slightly smaller than that of diesel. With the increase of injection pressure, the differences in spray penetration distance, spray cone angle and SMD between nano-fuel and diesel increase, and the differences are positively correlated with the mass concentration of nano-particles. When the jet ambient temperature rises, the differences in spray penetration distance and SMD between nano-fuel and diesel both increase, and in a high-temperature environment, the penetration distance and SMD of nano-fuel will gradually be smaller than those of diesel. The higher the mass concentration of nano-particles, the more obvious this phenomenon is, while the difference in spray cone angle decreases.

为了探究稀相纳米异质粒子对燃油射流喷雾特性的影响,基于纳米燃油喷雾可视化试验结果,应用计算流体力学软件建立含稀相纳米粒子的燃油喷雾模型,依据试验结果验证模型的准确性,并通过该模型研究喷油压力、环境温度和粒子质量浓度对CeO_2纳米燃油的喷雾特性的影响。研究结果表明:在相同喷射压力下,不同喷雾发展时刻,纳米燃油的油束贯穿距和索特平均直径(Sauter mean diameter, SMD)比柴油的大,喷雾锥角比柴油的略小。随着喷射压力提高,纳米燃油与柴油在喷雾贯穿距、喷雾锥角和SMD上的差异增大,且差异与纳米粒子质量浓度呈正相关。当射流环境温度上升时,纳米燃油与柴油在喷雾贯穿距和SMD上的差异均有所增加,且在高温环境下,纳米燃油的贯穿距和SMD会逐渐比柴油的小,纳米粒子质量浓度越高,该现象越明显,而喷雾锥角的差距有所减小。